Fix crash when placing call

// FREEBIE

Signal/src/call/OutboundCallInitiator.swift

@@ -50,6 +50,7 @@ import Foundation
         // Alternative way without prompting for permissions:
         // if AVAudioSession.sharedInstance().recordPermission() == .denied {
         AVAudioSession.sharedInstance().requestRecordPermission { isGranted in
+            DispatchQueue.main.async {
                 // Here the permissions are either granted or denied
                 guard isGranted == true else {
                     Logger.warn("\(self.TAG) aborting due to missing microphone permissions.")
@@ -58,6 +59,7 @@ import Foundation
                 }
                 callUIAdapter.startAndShowOutgoingCall(recipientId: recipientId)
             }
+        }
         return true
     }