fix: do not reduce count for subadmins if they are members of group

[Antreesy]

• Follow-up to fix: correctly count disabled users for subadmins #48437

Summary

Counter on sidebar doesn't reflect the actual number of group members, if subadmin is a member too.
For each group, counter is reduced by 1, and for 'All accounts', counter is reduced by amount of groups subadmin is in.

There is a comment:

we prevent subadmins from looking up themselves so we lower the count of the groups he belongs to

but I don't see a point of it, since we fetch and show yourself in the list anyway, so just removing inconsistency

Before	After
Subadmin: 'alice', member of 'test group' and 'test group 2'

TODO

• ...

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[provokateurin]

/backport to stable30

[provokateurin]

/backport to stable29

[provokateurin]

/backport to stable28

[Antreesy]

/backport to stable30