Revert "Use start instead of isolate, or NetworkManager will get stopped."

This reverts commit 2ed8cbd1.

The bta-no-usbpen was a link to /bin/sleep.

bin/bta-no-usbpen

+/bin/sleep
\ No newline at end of file

bin/get-config

@@ -213,7 +213,7 @@ start() {
             rm /local/iptables >/dev/null 2>&1
             rm /local/iptables.prev >/dev/null 2>&1
             rm /local/mk-homedir >/dev/null 2>&1
-            /usr/bin/systemctl start graphical && exit 0
+            /usr/bin/systemctl isolate graphical && exit 0
         fi
         echo "Fatal error(s): missing or wrong web service reply, abort."
         exit 1