Unclear that middle textbox in clone window doesn't want user typing

[mgorra]

When cloning a repo, there are three text boxes, the top and bottom of which want the user to type (and have gray text), and the middle of which (for the folder to place the repo in) wants the user to select from a side menu. Since the boxes are so similar, and the middle one shows an effect when clicked like the other do, it's unclear that it can't be typed in. The text box is necessary to show the filepath when selected, so maybe it should be grayed out beforehand?