glib2: Upgrade to 2.42.1

Signed-off-by: Ted Hess <thess@kitschensync.net>
upmpdcli: Revert #678 (force strip)

Signed-off-by: Ted Hess <thess@kitschensync.net>
Merge pull request #589 from thess/glib2-update

glib2: Upgrade to 2.42.1