rm registerUserQueue from UnitTests

* This queue was removed in this last commit of this PR and needs to be
removed so the test can run without errors.

Author: jkasten2

iOS_SDK/OneSignalSDK/UnitTests/UnitTestCommonMethods.h

@@ -62,7 +62,6 @@ NSString * serverUrlWithPath(NSString *path);
 
 // Expose OneSignal test methods
 @interface OneSignal (UN_extra)
-+ (dispatch_queue_t) getRegisterQueue;
 + (void)setDelayIntervals:(NSTimeInterval)apnsMaxWait withRegistrationDelay:(NSTimeInterval)registrationDelay;
 @end
 

iOS_SDK/OneSignalSDK/UnitTests/UnitTestCommonMethods.m

@@ -88,10 +88,6 @@ + (void)runBackgroundThreads {
         if (notifSettingsQueue)
             dispatch_sync(notifSettingsQueue, ^{});
 
-        registerUserQueue = [OneSignal getRegisterQueue];
-        if (registerUserQueue)
-            dispatch_sync(registerUserQueue, ^{});
-        
         [OneSignalClientOverrider runBackgroundThreads];
 
         [UNUserNotificationCenterOverrider runBackgroundThreads];