qt4-x11-free: Fix broken regexes in qt4-x11-free's recipe.
[YOCTO #1671]
qt4-x11-free's recipe includes a sed script to sanitize it's .prl files,
which are used by qmake to generate a list of libs and includes in the
Makefiles it generates. It however, fails to take into account the possibility
of trailing slashes, and thus leaves them in, and breaks gcc's syntax.
Update these regexes to account for them.
Signed-off-by: Wenzong Fan <wenzong.fan@windriver.com>
