HE.net authentication & domain not found error message about certbot-he-hook

[danielmotaleite]

This PR seems to fix this:
#6

[zaszlo]

Can confirm, that without that PR modification the script was failing, using its corrections is working.

Also on line 99 the return should be changed to exit, as that is an exit code and return can be used only from a function.
I was also getting this error:
/root/certbot-he-hook.sh: line 99: return: can only `return' from a function or sourced script

BR!

[NetForces]

I can also confirm that I was able to get wildcard certs with this patch.