Fix bug in SQLite query

The date recorded is the end of the collection, so we shouldn't add anything to it. It was implemented correctly for Postgres, but incorrectly for SQLite.

Author: Kobzol

database/src/pool/sqlite.rs

@@ -1153,7 +1153,7 @@ impl Connection for SqliteConnection {
     async fn last_artifact_collection(&self) -> Option<ArtifactCollection> {
         self.raw_ref()
             .query_row(
-                "select date_recorded + duration, duration \
+                "select date_recorded, duration \
                 from artifact_collection_duration \
                 order by date_recorded desc \
                 limit 1;",