Fix callback signature

The callback from Java/iOS now returns 3 arguments.
A small adjustment is needed to fix this, with regards to the cache feature.

src/android/src/main/java/com/RNFetchBlob/RNFetchBlobReq.java

            File file = new File(RNFetchBlobFS.getTmpPath(RNFetchBlob.RCTContext, cacheKey) + ext);
 
            if (file.exists()) {
-               callback.invoke(null, file.getAbsolutePath());
+               callback.invoke(null, null, file.getAbsolutePath());
                return;
            }
        }

src/ios/RNFetchBlobNetwork.m

 
     // the session trust any SSL certification
 
-    
+
     NSURLSessionConfiguration *defaultConfigObject = [NSURLSessionConfiguration defaultSessionConfiguration];
     if([options valueForKey:@"timeout"] != nil)
     {
 
 			destPath = [RNFetchBlobFS getTempPath:cacheKey withExtension:[self.options valueForKey:CONFIG_FILE_EXT]];
             if ([[NSFileManager defaultManager] fileExistsAtPath:destPath]) {
-				callback(@[[NSNull null], destPath]);
+				callback(@[[NSNull null], @[[NSNull null], destPath]);
                 return;
             }
 		}
 - (void) URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler
 {
     expectedBytes = [response expectedContentLength];
- 
+
     NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse*)response;
     NSInteger statusCode = [(NSHTTPURLResponse *)response statusCode];
     if ([response respondsToSelector:@selector(allHeaderFields)])
                      @"timeout" : @NO,
                      @"status": [NSString stringWithFormat:@"%d", statusCode ]
                      };
-        
+
         [self.bridge.eventDispatcher
          sendDeviceEventWithName: EVENT_STATE_CHANGE
          body:respInfo
     {
         [writeStream write:[data bytes] maxLength:[data length]];
     }
-    
+
     if([progressTable valueForKey:taskId] == @YES)
     {
         [self.bridge.eventDispatcher
 
 - (void) URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error
 {
-    
+
     self.error = error;
     [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
-    
+
     NSString * respType = [respInfo valueForKey:@"respType"];
     if(error != nil) {
         NSLog([error localizedDescription]);
     }
-    
+
     if(respFile == YES)
     {
         [writeStream close];
                    [respData base64EncodedStringWithOptions:0]
                    ]);
     }
-    
+
     [taskTable removeObjectForKey:taskId];
     [uploadProgressTable removeObjectForKey:taskId];
     [progressTable removeObjectForKey:taskId];