Blender Git Loki

Fix: tab completing a filepath name in file browsers asks to create a new
directory if name was not fully matched

When hitting tab to complete a directory name in the filepath field in the
filebrowser Blender shows a "create new directory?" popup, if the beginning
of directory name typed in the field matches many entries. For example if you
have directories in the open directory called "test123" and "test456", typing
"te", tab would complete up to "test", but ask to create a new folder with the
name "test".

This patch unsets the boolean storing the info about changing filepath if the
folder with the completed name does not exist.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D10