The default channel name in the ptgbot role defaults did not
correctly specify a starting hash which it requires, but also the
test jobs seem to need it set in the eavesdrop group vars specific
to testing.
Change-Id: I16cdeac4f7af50e2cac36c80d78f3a87f482e4aa
Set the channel we want ptgbot joining in production with a group
var, like we do for statusbot's channel list. Correct the password
var name to match what's used in the template for production (and
matches the override set in our private hostvars on the bastion).
Clean up the unnecessary auth nicks list which was copied from the
statusbot config but is entirely unused. Also get rid of some
unnecessary empty lines in the defaults as they really don't make
the file any more readable.
Change-Id: Id026b89d642eae13feba374e4f3ec610b543e530
