[FIX] quickadmin: Fix superfish arrow so it's visible on a white background (or black for darkroom) thanks luciash ;)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/11.x@46940 b456876b-0849-0410-b77d-98878d47e9d5
[MRG] Automatic merge, branches/11.x 46937 to 46940

git-svn-id: file:///var/local/code.tiki.org/tikisvn/trunk@46941 b456876b-0849-0410-b77d-98878d47e9d5