修复UIWebview 桥接方法失败问题

review by 枪兵

@@ -324,8 +324,8 @@
 
     [CDVUserAgentUtil acquireLock:^(NSInteger lockToken) {
         // Fix the memory leak caused by the strong reference.
+        [weakSelf setLockToken:lockToken];
         if (appURL) {
-            [weakSelf setLockToken:lockToken];
             NSURLRequest* appReq = [NSURLRequest requestWithURL:appURL cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:20.0];
             [self.webViewEngine loadRequest:appReq];
         }