typo in file.php

[mrmist]

A small typo in the FTP server request -

"To perform the requested action, WordPress needs to access to your web server"

I removed the first "to" in my patch, though either could go, I suppose.

Fix for typo issue reported in forums

This was reported in ​http://wordpress.org/support/topic/typo-in-the-host-access-form

(In [15593]) Fix typo. props mrmist, fixes #14571.