OverridingCategoryForSecurityProperty is not taking hipposys:members for hippo:group nodes into account

REPO-2285 introduced a fix and solution to support (and protect) specific security properties (userroles, groups, users) on hipposys:authrole, hipposys:group and hipposys:user nodes.

However there was one omission: the hipposys:members property for hipposys:group wasn't taken into account.

This is blocking bug, because without this override and not (and always!) explicitly defining the hipposys:members property and the required .meta:category: system and .meta:add-new-system-values: true, an existing hipposys:member property will get deleted on deployment!

Although the fix is trivial, it is super critical to correct this to prevent accidental errors like above.