Update failure block in OSStateSynchronizer.updateLanguage

* Added failure block in the else condition in OSStateSynchronizer.updateLanguage

Author: tanaynigam

iOS_SDK/OneSignalSDK/Source/OSStateSynchronizer.m

@@ -401,6 +401,11 @@ - (void)updateLanguage:(NSString * _Nonnull)language
         else if (results[OS_SMS] && results[OS_SMS][OS_SUCCESS] && [results[OS_SMS][OS_SUCCESS] boolValue]) {
             [OneSignalUserDefaults.initStandard saveStringForKey:OSUD_LANGUAGE withValue:language];
         }
+        else {
+            NSError *error = [NSError errorWithDomain:@"com.onesignal.language" code:0 userInfo:@{@"error" : @"Network Error"}];
+            failureBlock(error);
+            return;
+        }
 
         if (successBlock)
             successBlock(results);