Removed the unnecessary override and the !important from .wrap

In the sticky footer example there were some weird stuff..
Same fix for the navbar example of sticky footer
remove comma separating the color and the color-stop in -webkit-linear-gradient in the #gradient .vertical mixin.
Merge pull request #10729 from lipis/patch-2

Removed the unnecessary override and the !important from .wrap
Merge pull request #10893 from Shaun-Dychko/patch--webkit-linear-gradient

remove comma separating the color and the color-stop in -webkit-linear-gradient in the #gradient .vertical mixin.
run grunt on last commit for gradient syntax change