Fix reindex broken by removing entries from multimap

Change I01f94ec8dea2cad352cc4766eb932d380f7bb065 broke the
reindexer somehow by removing entries from the list in the
mutlimap.  Make a copy of the list before removing entries from it.

Change-Id: I7add5639f06c7607b00f99f2873f70d53c7df33b
1 file changed