Bump up launch screen logo size on iPhone6 and larger

The previous launch screen was initially built on iphone5, but we never
scaled the logo to have the same proportions on iphone6 and larger
screens. Now it's scaled proportional to the screen width.

// FREEBIE

Signal/src/util/Launch Screen.storyboard

@@ -1,9 +1,14 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="10116" systemVersion="15D21" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" initialViewController="01J-lp-oVM">
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="11542" systemVersion="15G1108" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" colorMatched="YES" initialViewController="01J-lp-oVM">
+    <device id="retina4_7" orientation="portrait">
+        <adaptation id="fullscreen"/>
+    </device>
     <dependencies>
         <deployment identifier="iOS"/>
-        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="10085"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="11524"/>
         <capability name="Aspect ratio constraints" minToolsVersion="5.1"/>
+        <capability name="Constraints with non-1.0 multipliers" minToolsVersion="5.1"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
     </dependencies>
     <scenes>
         <!--View Controller-->
@@ -15,21 +20,19 @@
                         <viewControllerLayoutGuide type="bottom" id="xb3-aO-Qok"/>
                     </layoutGuides>
                     <view key="view" contentMode="scaleToFill" id="Ze5-6b-2t3">
-                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
                             <imageView userInteractionEnabled="NO" contentMode="scaleToFill" horizontalHuggingPriority="251" verticalHuggingPriority="251" image="logoSignal" translatesAutoresizingMaskIntoConstraints="NO" id="b92-yg-YYQ">
-                                <rect key="frame" x="253" y="253" width="94" height="94"/>
+                                <rect key="frame" x="125" y="271" width="125" height="125"/>
                                 <constraints>
                                     <constraint firstAttribute="width" secondItem="b92-yg-YYQ" secondAttribute="height" multiplier="1:1" id="K4Q-zJ-faE"/>
-                                    <constraint firstAttribute="width" constant="96" id="m7K-Or-1Pe" userLabel="width = 94">
-                                        <variation key="heightClass=compact" constant="64"/>
-                                    </constraint>
                                 </constraints>
                             </imageView>
                         </subviews>
-                        <color key="backgroundColor" red="0.12549019607843137" green="0.56470588235294117" blue="0.91764705882352937" alpha="1" colorSpace="calibratedRGB"/>
+                        <color key="backgroundColor" red="0.12549019607843137" green="0.56470588235294117" blue="0.91764705882352937" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
                         <constraints>
+                            <constraint firstItem="b92-yg-YYQ" firstAttribute="width" secondItem="Ze5-6b-2t3" secondAttribute="width" multiplier="1:3" id="d0v-ZC-EgJ"/>
                             <constraint firstItem="b92-yg-YYQ" firstAttribute="centerY" secondItem="Ze5-6b-2t3" secondAttribute="centerY" id="ec1-lk-fbn"/>
                             <constraint firstItem="b92-yg-YYQ" firstAttribute="centerX" secondItem="Ze5-6b-2t3" secondAttribute="centerX" id="jLr-XH-MKf"/>
                         </constraints>