[iOS] WXCoreBridge install should run in main thread

Author: jianhan-he

ios/sdk/WeexSDK/Sources/Bridge/WXBridgeContext.m

@@ -144,8 +144,6 @@ - (void)registerGlobalFunctions
         return [weakSelf invokeNative:instance tasks:tasks callback:callback];
     }];
 
-    [WXCoreBridge install];
-    
     [_jsBridge registerCallUpdateComponentData:^NSInteger(NSString *instanceId, NSString *componentId, NSString *jsonData) {
         if (_dataRenderHandler) {
             WXPerformBlockOnComponentThread(^{