Fix marcuswestin#41 - remove __block to avoid losing callbackId. See http://developer.apple.com/library/ios/#documentation/cocoa/conceptual/Blocks/Articles/bxVariables.html "Types of variables" marcuswestin#3 and marcuswestin#4 - we want callbackId to be non-mutable, const

Author: marcuswestin

WebViewJavascriptBridgeAbstract/WebViewJavascriptBridgeAbstract.m

@@ -111,7 +111,7 @@ - (void)_flushMessageQueue {
             [self.responseCallbacks removeObjectForKey:responseId];
         } else {
             WVJBResponseCallback responseCallback = NULL;
-            __block NSString* callbackId = message[@"callbackId"];
+            NSString* callbackId = message[@"callbackId"];
             if (callbackId) {
                 responseCallback = ^(id responseData) {
                     NSDictionary* msg = @{ @"responseId":callbackId, @"responseData":responseData };