Admin bar menu width fix

[niklasbr]

This cosmetic issue crops up when you have an especially long site name or are in the network admin section of a multi site.

The drop down menu does not keep the width of the link on the bar itself (see the before image). Changing the min-width to 100% will ensure that the drop down menu expands to fill in the available with made by the link in the admin bar while at the same time allowing longer items in the menu to expand that width even further.

[niklasbr]

After image

[niklasbr]

Before image

[duck_]

Duplicate of #19139.

[niklasbr]

Thanks, now I feel stupid that my attempt to search for this issue in other tickets failed.