Add a check to ensure archiveserver is set

In headless mode, the image rc.local is used. It should get replaced outside of setup, but replacing it just in case. Only takes action in headless mode.

setup/pi/setup-teslausb

@@ -48,6 +48,7 @@ function headless_setup_mark_setup_success () {
 
     rm /boot/TESLAUSB_SETUP_STARTED
     touch /boot/TESLAUSB_SETUP_FINISHED
+    # This sed shouldn't be needed, but double checking just to be sure. 
     sed -i'.bak' -e "s/TEMPARCHIVESERVER/$archiveserver/g" /etc/rc.local
     setup_progress "Main setup completed. Remounting file systems read only."
   fi