Fix assert during calls without camera permission.

// FREEBIE

Signal/src/UIApplication+OWS.swift

@@ -6,12 +6,25 @@ import Foundation
 
 extension UIApplication {
 
+    var frontmostViewControllerIgnoringAlerts: UIViewController? {
+        return findFrontmostViewController(ignoringAlerts:true)
+    }
+
     var frontmostViewController: UIViewController? {
+        return findFrontmostViewController(ignoringAlerts:false)
+    }
+
+    internal func findFrontmostViewController(ignoringAlerts: Bool) -> UIViewController? {
         let window = UIApplication.shared.keyWindow
         var viewController = window!.rootViewController
-        
+
         while true {
             if let nextViewController = viewController?.presentedViewController {
+                if ignoringAlerts {
+                    if nextViewController as? UIAlertController != nil {
+                        break
+                    }
+                }
                 viewController = nextViewController
             } else if let navigationController = viewController as? UINavigationController {
                 if let nextViewController = navigationController.topViewController {

Signal/src/call/CallService.swift

@@ -79,7 +79,7 @@ enum CallError: Error {
 }
 
 // Should be roughly synced with Android client for consistency
-fileprivate let connectingTimeoutSeconds = 120
+private let connectingTimeoutSeconds = 120
 
 // All Observer methods will be invoked from the main thread.
 protocol CallServiceObserver: class {
@@ -1621,9 +1621,10 @@ protocol CallServiceObserver: class {
             return
         }
 
-        guard nil != UIApplication.shared.frontmostViewController as? CallViewController else {
+        let frontmostViewController = UIApplication.shared.frontmostViewControllerIgnoringAlerts
+            guard nil != frontmostViewController as? CallViewController else {
             OWSProdError(OWSAnalyticsEvents.callServiceCallViewCouldNotPresent(), file:#file, function:#function, line:#line)
-            owsFail("\(TAG) in \(#function) Call terminated due to call view presentation delay.")
+            owsFail("\(TAG) in \(#function) Call terminated due to call view presentation delay: \(frontmostViewController.debugDescription).")
             self.terminateCall()
             return
         }