fix compiler warnings

// FREEBIE

Signal/src/ViewControllers/ModalActivityIndicatorViewController.swift

@@ -67,7 +67,7 @@ class ModalActivityIndicatorViewController: OWSViewController {
     override func loadView() {
         super.loadView()
 
-        self.view.backgroundColor = UIColor(colorLiteralRed: 0, green: 0, blue: 0, alpha: 0.25)
+        self.view.backgroundColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.25)
         self.view.isOpaque = false
 
         let activityIndicator = UIActivityIndicatorView(activityIndicatorStyle:.whiteLarge)

Signal/src/environment/ExperienceUpgrades/ExperienceUpgrade.swift

@@ -28,7 +28,7 @@ class ExperienceUpgrade: TSYapDatabaseObject {
         super.init(uniqueId: uniqueId)
     }
 
-    required init!(coder: NSCoder!) {
+    required init!(coder: NSCoder) {
         // This is the unfortunate seam between strict swift and fast-and-loose objc
         // we can't leave these properties nil, since we really "don't know" that the superclass
         // will assign them.