fix detecting cyclic group memberships

[blizzz]

When there is a cyclic group membership of groups (AD, Samba4), this was not being detected as not all information was taken into account, resulting in an infinite loop.

To reproduce:

1. In AD/Samba4 have three groups Group A, Group B and Group C.
2. Group B is member of Group A, Group C is member of Group B and Group A is member of Group C.
3. LDAP settings Nested groups are enabled and hasMemberOfFilterSupport is disabled.
4. php occ group:list

[blizzz]

/backport to stable21

[blizzz]

/backport to stable20

[blizzz]

/backport to stable19

[ChristophWurst]

I know some of these words

[awaw9]

في الجمعة، ٢٦ فبراير ٢٠٢١ ١٢:٥٨ م blizzz <notifications@github.com> كتب:

…

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[tofuSCHNITZEL]

LGTM.
while checking the code and testing it with my local setup I found a rather small and simple addition to make the nested groups work with non DN group member attribute groups. you can check it out here:
tofuSCHNITZEL@5bf4fea
if it makes sense we could include it also here since its a rather small fix. (I tested it with my zimbra ldap - but I guess it should be tested with another ldap that uses eg uid as a member attribute as well.)

[blizzz]

LGTM.
while checking the code and testing it with my local setup I found a rather small and simple addition to make the nested groups work with non DN group member attribute groups. you can check it out here:
tofuSCHNITZEL@5bf4fea
if it makes sense we could include it also here since its a rather small fix. (I tested it with my zimbra ldap - but I guess it should be tested with another ldap that uses eg uid as a member attribute as well.)

Nice one. I am happy to take it, but prefer it in a follow up PR for issue separation.