FileSharkPl: corrected login procedure to reuse cookies

git-svn-id: svn://svn.jdownloader.org/jdownloader/trunk@26177 ebf7c1c2-ba36-0410-9fe8-c592906822b4
-Improved Stv

git-svn-id: svn://svn.jdownloader.org/jdownloader/trunk@26178 ebf7c1c2-ba36-0410-9fe8-c592906822b4