rlm_sql: default Acct-On/Off query for all backends is somewhat bogus

[Alan DeKok]

Stefan Winter wrote:
> ... I suggest to change the WHERE to
> 
> ~          WHERE acctstoptime      =  NULL \
> ~          AND nasipaddress      =  '%{NAS-IP-Address}' \
> ~          AND acctstarttime     <= '%S'"
> 
> (leaving out the acctsessiontime = 0 constraint)

  Updated.

  Please test.

  Alan DeKok.