No, its fine to keep it on.
Just run the steps to activate
19. Open "SAM" under "Utilties" select "De-Activate iPhone", "Revert lockdown", and then select "Restore Activation"
20. Plug into iTunes, and wait for activation.
-If you get a iTunes Error saying invalid sim, go back into "SAM" and make sure "Auto Detect" is selected at the main menu.
-Once your phone loads up in iTunes, check SAM under "More Information" & look for Activation Status to read "WildcardActivated"
and you should be fine