scripts/modules.sh: move site feeds to the front of the module list

We don't want OpenWrt packages to replace Gluon packages by accident;
the same logic applies to packages from site feeds.

This gives site feeds a higher precedence than gluon/packages, but that
is unlikely to cause any issues. Gluon base packages still have an even
higher precedence.

(cherry picked from commit a20a25e)

scripts/modules.sh

@@ -2,7 +2,7 @@
 [ ! -f "$GLUON_SITEDIR"/modules ] || . "$GLUON_SITEDIR"/modules
 
 # shellcheck disable=SC2086
-FEEDS="$(echo $GLUON_FEEDS $GLUON_SITE_FEEDS | tr ' ' '\n')"
+FEEDS="$(echo $GLUON_SITE_FEEDS $GLUON_FEEDS | tr ' ' '\n')"
 
 GLUON_MODULES=openwrt