Optional admin email address

src/freedombone-notification

@@ -71,7 +71,10 @@ fi
 if [ ! "$ADMIN_USERNAME" ]; then
     ADMIN_USERNAME=$(grep "Admin user" "$COMPLETION_FILE" | awk -F ':' '{print $2}')
 fi
-ADMIN_EMAIL_ADDRESS=${ADMIN_USERNAME}@${HOSTNAME}
+
+if [ ! "$ADMIN_EMAIL_ADDRESS" ]; then
+    ADMIN_EMAIL_ADDRESS=${ADMIN_USERNAME}@${HOSTNAME}
+fi
 
 # send email to administrator
 if [ "$SUBJECT" ]; then