chore(ios): suppress unreachable code compile warning

we check for iOS < 10 in order to specifically emit a warning that
it is not supported, naturally in the test app (which is iOS 11)
this generates a warning for unreachable code

Author: mikehardy

packages/messaging/ios/RNFBMessaging/RNFBMessagingModule.m

@@ -257,7 +257,10 @@ - (NSDictionary *)constantsToExport {
   resolve(@([RCTConvert BOOL:@(YES)]));
   return;
 #endif
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunreachable-code"
   if (@available(iOS 10.0, *)) {
+#pragma pop
     if ([UIApplication sharedApplication].isRegisteredForRemoteNotifications == YES) {
       resolve(@([RCTConvert BOOL:@(YES)]));
       return;