net/mwan3: add mwan3_init function

Move all shell commands which are executed during /lib/mwan3/mwan3.sh
sourceing into a seperate init function which must be called at first.

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

net/mwan3/files/usr/sbin/mwan3

@@ -187,6 +187,7 @@ restart() {
 
 case "$1" in
 	ifup|ifdown|interfaces|policies|connected|rules|status|start|stop|restart)
+		mwan3_init
 		$*
 	;;
 	*)