Bug 4254 - adding new patron advanced notice doesn't save

Bug 4254 - adding new patron advanced notice doesn't save

This was due to poorly constructed SQL which returned duplicate values for
certain fields. This patch corrects that SQL.

NOTE: There is also a formatting problem with the message prefs display table
when it is displayed in moremember.pl. This is due to there being no logic to
tell the table in that context to display checkboxes as appropriate. This patch
does not fix that. Bug 5328 has been opened for this problem.

Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>