Security level requires a restart in a new profile after 148 update

On the 148 branch, launching a fresh profile will present the user with "Your security level settings require a restart".

This is because upstream changed the default value of javascript.options.asmjs from true to false. See #44686 (closed). The "standard" security level (level 4), expects this to be false. So the restart is requested to flip the value.

We should either set javascript.options.asmjs back to true in our default preferences, or we should change all security levels to be false instead.