search does not always find one-to-one chat

[r10s]

i have one recent one-to-one chat that cannot be found by the global search; the chat is there and even recently used, but typing in its name, it is not displayed in the search result.

i assume, that chat.name is somehow not set accordingly, i'll investigate a bit and try to create a failing test.

maybe related to deltachat/deltachat-ios#1505 (that was closed that time as reproducing fails)