changed title bar color to be exactly the same as studip's jquery dialog; note that studip's as well as ckeditor's colors get modified by some unknown effect and therefore colors where measured when displayed and modified by trial-and-error

git-svn-id: svn://develop.studip.de/studip/trunk@29243 c5b85792-5220-0410-ad23-ed5b6b8ad999