When I sync my iPhone it connects to external drive

It is just a nuisance, but I cannot figure out how to stop it from happening. I have gone through all of the menu items in iTunes (iPhone) and iTunes preferences itself. But every time I plug it in, it tries to connect (unsuccessfully) to an old drive share I had on the network, a computer that no longer exists. Can anyone tell me where this record is being stored ( in my iTunes or iPhone) and how to turn it off?

(the sync continues fine after I click through this annoying box.

https://www.dropbox.com/s/1w5qyarra3avh5t/Screenshot%202015-08-22%2017.12.33.png ?dl=0