journaldb:  Fix that fileid might be missing in the db

When recovering from a inalid move operation, we call
avoidReadFromDbOnNextSync. This will remove the fileid from the db so
we don't detect a move on the next sync.  But we want the next sync to fetch
the file id again, and this can only happen if we don't read them
from the db and do the actual PROPFIND, this is done by avoidReadFromDbOnNextSync

However, if there is propagation in that source directory later, it
will overide the invalid etag with the real one and we will not uissue the PROPFIND
to fetch the fileid.
We must therefore also protect the future write to the DB when calling
avoidReadFromDbOnNextSync