Revert "[qtcontacts-sqlite] Remove check for IsNot relationships"

This reverts commit 50d0d5c838b4aab51e026dc36cabfaac0ee7b850.
[qtcontacts-sqlite] Respond to relationship changes

If changes to relationships cause constituent contacts to become
disaggregated, or aggregates to become childless, then remove or
generate new aggregates as required to maintain order.