Core: fix internal webhooks (#649)

* fix internal webhooks

* argument annotation

lnbits/core/crud.py

@@ -180,13 +180,18 @@ async def get_wallet_for_key(
 
 
 async def get_standalone_payment(
-    checking_id_or_hash: str, conn: Optional[Connection] = None
+    checking_id_or_hash: str,
+    conn: Optional[Connection] = None,
+    incoming: Optional[bool] = False,
 ) -> Optional[Payment]:
+    clause: str = "checking_id = ? OR hash = ?"
+    if incoming:
+        clause = f"({clause}) AND amount > 0"
     row = await (conn or db).fetchone(
-        """
+        f"""
         SELECT *
         FROM apipayments
-        WHERE checking_id = ? OR hash = ?
+        WHERE {clause}
         LIMIT 1
         """,
         (checking_id_or_hash, checking_id_or_hash),