A big warning when modify it can lead to "raise condition" when you modifiy the file outside your Jolla may have cached contents internally.

Also make backup and don't be as stupid as me. Second it seems the file is cashed in ram after account created, atleast for sometime, probadly why you don't see it.

In my case mistakely copied from my N9 Sailfish edition using scp modified it with sqlitebrowser and copied back to my new Jolla(dumb me). Everything stoped to work (suprise... not...)

So I decided to wipe all account related(could not remove from UI so i did rm account* and rebooted) and create all account from start then reboot => copy2laptop => modify => copy2jolla.

But in your case you proabadly better reboot to make sure contents actually has been stored on emmc then copy to laptop modify it. overwrite modified and reboot.

But again not sure modify this way is the best way. Maybe it can be done via dbus/gconf directly on phone or whatever to avoid raise...

Oh forgot in my case I still can't send mail so in my case its totally pointless to try this :/But atleast I learned something. Make backup