Fix SQL query for last connection attempts where FreeRADIUS is v3.

[MiguelVis]

Possibly a fix for #58.

Potential bug in rep-lastconnect.php if we are running daloRADIUS under FreeRadius 3 and we have set $configValues['FREERADIUS_VERSION'] to the value '3':

	if (isset($configValues['FREERADIUS_VERSION']) && ($configValues['FREERADIUS_VERSION'] == '2')) {
		$tableSetting['postauth']['user'] = 'username';
		$tableSetting['postauth']['date'] = 'authdate';
	} elseif (isset($configValues['FREERADIUS_VERSION']) && ($configValues['FREERADIUS_VERSION'] == '1')) {
		$tableSetting['postauth']['user'] = 'user';
		$tableSetting['postauth']['date'] = 'date';
	}

If that is the case, both $tableSetting['postauth']['user'] and $tableSetting['postauth']['date'] will be undefined, so the SQL queries would be bad formed:

$sql = "SELECT ".
			$configValues['CONFIG_DB_TBL_RADPOSTAUTH'].".".$tableSetting['postauth']['user']." 
		FROM ".$configValues['CONFIG_DB_TBL_RADPOSTAUTH']. 
        " WHERE (".$configValues['CONFIG_DB_TBL_RADPOSTAUTH'].".".$tableSetting['postauth']['user']." LIKE '".
	$dbSocket->escapeSimple($usernameLastConnect)."%') $radiusReplySQL ".
		" AND (".$tableSetting['postauth']['date']." >='$startdate' AND ".$tableSetting['postauth']['date']." <='$enddate') ";