Fix keychain warning alert showing app on app launch, if keychain is locked

This could happen if the app is launched via background fetch right when the device started and before it is unlocked by the user.

Classes/BITAuthenticator.m

@@ -108,19 +108,19 @@ static unsigned char kBITPNGEndChunk[4] = {0x49, 0x45, 0x4e, 0x44};
   
   // make sure this is called after startManager so all modules are fully setup
   if (!_isSetup) {
+    [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(authenticateInstallation) object:nil];
     [self performSelector:@selector(authenticateInstallation) withObject:nil afterDelay:0.1];
+  } else {
+    switch ([[UIApplication sharedApplication] applicationState]) {
+      case UIApplicationStateActive:
+        [self authenticate];
+        break;
+      case UIApplicationStateBackground:
+      case UIApplicationStateInactive:
+        // do nothing, wait for active state
+        break;
+    }
   }
-  
-  switch ([[UIApplication sharedApplication] applicationState]) {
-    case UIApplicationStateActive:
-      [self authenticate];
-      break;
-    case UIApplicationStateBackground:
-    case UIApplicationStateInactive:
-      // do nothing, wait for active state
-      break;
-  }
-  
   [self registerObservers];
 }
 
@@ -156,6 +156,10 @@ static unsigned char kBITPNGEndChunk[4] = {0x49, 0x45, 0x4e, 0x44};
 }
 
 - (void)alertOnFailureStoringTokenInKeychain {
+  if ([[UIApplication sharedApplication] applicationState] != UIApplicationStateActive) {
+    return;
+  }
+
   UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:nil
                                                       message:BITHockeyLocalizedString(@"HockeyAuthenticationViewControllerStorageError")
                                                      delegate:self