package/x11r7/xlib_libX11: don't require static libc on host

package/x11r7/xlib_libX11: don't require static libc on host

As per: https://gitlab.freedesktop.org/xorg/lib/libx11/commit/4645e219133458781e3fb48eaea6a74cccb1b9aa

"For Windows targets, libtool uses a wrapper executable, not a wrapper
script (see [1]), which it compiles with the host compiler.  This
doesn't work when cross-compiling."

Because of this change, builds fail on Linux hosts without a static
libc. This patch reverts this change as we are guaranteed to build in a
Linux environment.

Fixes:
http://autobuild.buildroot.net/results/ac7c777e5fe31b6eda8b8b662881b07299e57ae9

Signed-off-by: Adam Duskett <Aduskett@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>