Marco Trevisan authored Nov 05, 2018 and Philip Withnall committed Nov 06, 2018

This was causing a crash, because we were first removing an item, freeing
both the instance itself and the key, and then trying to reuse those.

So, in this case, instead of reassigning an item, we can just return TRUE
as we have already the item at the right place, while it's not needed to
update the modified timestamp, since no modification happened in reality.

Fixes #1588