PAM authentication uses a regular expression to extract the user's real
name from the 'user name or comment field' passwd file when creating a
new account.
The current regular expression assumes the comment field contains the
user name followed by a comma and some other comma-delimited information
(the Linux 'adduser' command adds room number, work phone, home phone
and 'other' info given half a chance).
If the field just contains the user name, there is no trailing comma
and the RE match fails. Make the trailing comma optional.
Signed-off-by: Andrew McMillan <andrew@morphoss.com>