remove unneccessary hack

Now that we have a nice system message design, we don't need to shoe
horn group updates into the TSCall adapter.

// FREEBIE

Signal/src/Models/OWSCall.h

@@ -15,9 +15,9 @@ typedef enum : NSUInteger {
     kCallMissed = 3,
     kCallOutgoingIncomplete = 4,
     kCallIncomingIncomplete = 5,
-    // kGroupUpdateJoin has been deprecated.
-    kGroupUpdateLeft = 7,
-    kGroupUpdate = 8,
+    // kGroupUpdateJoin = 6, has been deprecated.
+    // kGroupUpdateLeft = 7, has been deprecated.
+    // kGroupUpdate = 8, has been deprecated.
     kCallMissedBecauseOfChangedIdentity = 9,
 } CallStatus;
 
@@ -26,14 +26,6 @@ typedef enum : NSUInteger {
 #pragma mark - Initialization
 
 - (instancetype)initWithCallRecord:(TSCall *)callRecord;
-
-- (instancetype)initWithInteraction:(TSInteraction *)interaction
-                           callerId:(NSString *)senderId
-                  callerDisplayName:(NSString *)senderDisplayName
-                               date:(nullable NSDate *)date
-                             status:(CallStatus)status
-                      displayString:(NSString *)detailString NS_DESIGNATED_INITIALIZER;
-
 - (instancetype)init NS_UNAVAILABLE;
 
 /*

Signal/src/Models/TSMessageAdapaters/TSMessageAdapter.m

@@ -224,28 +224,6 @@ NS_ASSUME_NONNULL_BEGIN
         adapter.infoMessageType    = infoMessage.messageType;
         adapter.messageBody        = infoMessage.description;
         adapter.messageType        = TSInfoMessageAdapter;
-        if (adapter.infoMessageType == TSInfoMessageTypeGroupQuit ||
-            adapter.infoMessageType == TSInfoMessageTypeGroupUpdate) {
-            // repurposing call display for info message stuff for group updates, ! adapter will know because the date
-            // is nil.
-            //
-            // TODO: I suspect that we'll want a separate model
-            //       that conforms to <OWSMessageData> for info
-            //       messages.
-            CallStatus status = 0;
-            if (adapter.infoMessageType == TSInfoMessageTypeGroupQuit) {
-                status = kGroupUpdateLeft;
-            } else if (adapter.infoMessageType == TSInfoMessageTypeGroupUpdate) {
-                status = kGroupUpdate;
-            }
-            OWSCall *call = [[OWSCall alloc] initWithInteraction:interaction
-                                                        callerId:@""
-                                               callerDisplayName:adapter.messageBody
-                                                            date:nil
-                                                          status:status
-                                                   displayString:@""];
-            return call;
-        }
     } else if ([interaction isKindOfClass:[TSUnreadIndicatorInteraction class]]) {
         adapter.messageType = TSUnreadIndicatorAdapter;
     } else if ([interaction isKindOfClass:[TSErrorMessage class]]) {