Fixing the uid Column isn't unique.

uid is required to be unique for the the Changed Events (with the new Data) to be inserted without creating new Rows.

sql/events/events_delete_duplicate_rows.sql

@@ -0,0 +1,6 @@
+DELETE FROM events
+WHERE rowid NOT IN (
+  SELECT MIN(rowid)
+  FROM events
+  GROUP BY uid
+);