SQL Ledger can’t view Open POS Invoice

On Line 2333 of SL/Form.pm add single quotes to $expires variable

# remove expired locks
$query = qq|DELETE FROM semaphore
WHERE expires < '$expires'|;
$dbh->do($query) || $self->dberror($query);

Error:
**DBD::Pg::db do failed: ERROR: operator does not exist: character varying < integer
LINE 2: WHERE expires < 1204510587
^
HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.
*

Error!

*DELETE FROM semaphore
WHERE expires < 1204510587
ERROR: operator does not exist: character varying < integer
LINE 2: WHERE expires < 1204510587
^
HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.