makepkg: fix abortion after sourcing /etc/profile

The source command triggers / might trigger the ERR trap which makes
makepkg abort right after a successful installation of missing
dependencies.

Thanks to Xavier Chantry <shiningxc@gmail.com> for finding this
solution.

Signed-off-by: Cedric Staniewski <cedric@gmx.ca>
Signed-off-by: Xavier Chantry <shiningxc@gmail.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

scripts/makepkg.sh.in

@@ -371,10 +371,11 @@ handle_deps() {
 	fi
 
 	# we might need the new system environment
-	# set -e can cause problems during sourcing profile scripts
-	set +e
+	# avoid triggering the ERR trap
+	local restoretrap=$(trap -p ERR)
+	trap - ERR
 	source /etc/profile &>/dev/null
-	set -e
+	eval $restoretrap
 
 	return $R_DEPS_SATISFIED
 }