Delete /dev/shm/FTL-* files on (re)start of pihole-FTL

Signed-off-by: DL6ER <dl6er@dl6er.de>

advanced/Templates/pihole-FTL.service

@@ -33,6 +33,8 @@ start() {
     mkdir -p /var/run/pihole
     mkdir -p /var/log/pihole
     chown pihole:pihole /var/run/pihole /var/log/pihole
+    # Remove possible leftovers from previous pihole-FTL processes
+    rm -f /dev/shm/FTL-* 2> /dev/null
     rm /var/run/pihole/FTL.sock 2> /dev/null
     # Ensure that permissions are set so that pihole-FTL can edit all necessary files
     chown pihole:pihole /run/pihole-FTL.pid /run/pihole-FTL.port