HostGroup edit fails when director/filter/hostgroups is active

[okrouhly]

Expected Behavior

Work as normal editation (at least allow Assign where changes) of given Group to users that has allowed that group by director/filter/hostgroup setting.
Solving that issue may be a partial workarround to issue #2163

Current Behavior

An error occures when trying to edit given Host Group:
SQLSTATE[42S22]: Column not found: 1054 Unknown column 'o.object_name' in 'where clause', query was: SELECT h.id FROM icinga_hostgroup AS h WHERE (id = '4') AND (o.object_name IN ('Linux'))

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'o.object_name' in 'where clause'

Possible Solution

Change function filterHostGroupsQuery default argument to $tableAlias = 'h' instead of current value 'o' at file library/Director/Restriction/HostgroupRestriction.php

Steps to Reproduce (for bugs)

• Limit user role to access only some Host Groups in Icinga Director by setting director/filter/hostgroups to correct value/name(s) of existing Host Group(s).
• Logout/Login with that role.
• Try to edit given Host Group with that user, an error above will be displayed.

Your Environment

• Director version (System - About): 1.7.2 or older (tested also on 1.6.2)
• Icinga Web 2 version and modules (System - About): N/A
• Icinga 2 version (icinga2 --version): N/A
• Operating System and version: N/A
• Webserver, PHP versions: N/A

[formorer]

I am also facing that Problem with a recent Director and the simple fix also fixes it here.