compile-medialibrary.sh: force uid/gid during tarball extraction

Under rare circonstances, tar will try to preserve uid/gid no matter what,
and fail.
This can happen for example when trying to build the contribs/extras as a
privileged user inside a namespaced container.
4 jobs for !180 with medialib-compile-tar-fix in 23 minutes and 58 seconds (queued for 3 seconds)
detached
Status Job ID Name Coverage
  Build
passed #291566
android debian
build-ml-arm64

00:22:27

passed #291567
android debian
build-ml-armv7

00:23:42

passed #291568
android debian
build-ml-x86

00:23:31

passed #291569
android debian
build-ml-x86_64

00:23:57