Correctly test for HMR parameter in the bundle URL

Summary: Closes https://github.com/facebook/react-native/pull/7525

Differential Revision: D3292314

Pulled By: javache

fbshipit-source-id: 04090f7f1253e055278a6774f7e135833ae3d6f6

React/Base/RCTBatchedBridge.m

@@ -474,7 +474,7 @@ RCT_EXTERN NSArray<Class> *RCTGetModuleClasses(void);
 
 #if RCT_DEV
 
-  if (RCTGetURLQueryParam(self.bundleURL, @"hot")) {
+  if ([RCTGetURLQueryParam(self.bundleURL, @"hot") boolValue]) {
     NSString *path = [self.bundleURL.path substringFromIndex:1]; // strip initial slash
     NSString *host = self.bundleURL.host;
     NSNumber *port = self.bundleURL.port;