Fix recurring task crash

It would fail when inserting a commit into the queue that was already in
the queue, instead of just skipping that commit.

.sqlx/query-9d51c90afa966740bbd7801c3e6736821d2ab899a6390ec1b66a2067cbcadc25.json

@@ -0,0 +1,12 @@
+{
+  "db_name": "SQLite",
+  "query": "INSERT OR IGNORE INTO queue (hash, date) VALUES (?, ?)",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Right": 2
+    },
+    "nullable": []
+  },
+  "hash": "9d51c90afa966740bbd7801c3e6736821d2ab899a6390ec1b66a2067cbcadc25"
+}