Fix black colored text in suggestions when activated with keydown

bug also happens simply when typing to add a new site link, with no keydown.

Fix appears to be to apply color: black only to  .ui-suggester-list a
and not to .ui-suggester-list .ui-ooMenu-item a

[Bug: 68386](https://bugzilla.wikimedia.org/show_bug.cgi?id=68386)