prevent insert nil into dic

&#36828;&#23576; · &#36828;&#23576; · commit 1dc02737d14c · 2014-03-12T10:53:59.000+08:00
diff --git a/WebViewJavascriptBridge/WebViewJavascriptBridge.m b/WebViewJavascriptBridge/WebViewJavascriptBridge.m
@@ -172,6 +172,10 @@ - (void)_flushMessageQueue {
             NSString* callbackId = message[@"callbackId"];
             if (callbackId) {
                 responseCallback = ^(id responseData) {
+                    if (responseData == nil) {
+                        responseData = @{};
+                    }
+                    
                     WVJBMessage* msg = @{ @"responseId":callbackId, @"responseData":responseData };
                     [self _queueMessage:msg];
                 };
