Make cast explicit

Classes/Network/PonyDebugger/FLEXNetworkObserver.m

@@ -1156,7 +1156,7 @@ static char const * const kFLEXRequestIDKey = "kFLEXRequestIDKey";
         FLEXInternalRequestState *requestState = [self requestStateForRequestID:requestID];
 
         if (!requestState.dataAccumulator) {
-            NSUInteger unsignedBytesExpectedToWrite = totalBytesExpectedToWrite > 0 ? totalBytesExpectedToWrite : 0;
+            NSUInteger unsignedBytesExpectedToWrite = totalBytesExpectedToWrite > 0 ? (NSUInteger)totalBytesExpectedToWrite : 0;
             requestState.dataAccumulator = [[NSMutableData alloc] initWithCapacity:unsignedBytesExpectedToWrite];
             [[FLEXNetworkRecorder defaultRecorder] recordResponseReceivedWithRequestID:requestID response:downloadTask.response];