Problem/Motivation
When a source string is deleted, the wrong locales_location record is deleted because the query uses the wrong key. It deletes a location record for a different string. This can cause future translation updates to the second string to not take effect since its location record is missing.
Steps to reproduce
TBD
Proposed resolution
Fix the delete query condition for the locales_location table.
Remaining tasks
A functional test of the update problem as explained in the issue summary.
