Update AppRTCDemo AppRTC URL's on iOS to appr.tc

BUG=webrtc:5886

Review-Url: https://codereview.webrtc.org/1990903002
Cr-Commit-Position: refs/heads/master@{#12805}
diff --git a/webrtc/examples/objc/AppRTCDemo/ios/ARDAppDelegate.h b/webrtc/examples/objc/AppRTCDemo/ios/ARDAppDelegate.h
index c73e8f2..64b06a3 100644
--- a/webrtc/examples/objc/AppRTCDemo/ios/ARDAppDelegate.h
+++ b/webrtc/examples/objc/AppRTCDemo/ios/ARDAppDelegate.h
@@ -12,6 +12,6 @@
 
 // The main application class of the AppRTCDemo iOS app demonstrating
 // interoperability between the Objective C implementation of PeerConnection
-// and the apprtc.appspot.com demo webapp.
+// and the appr.tc demo webapp.
 @interface ARDAppDelegate : NSObject <UIApplicationDelegate>
 @end