fix: don't iterate on None from gen_metadata key

`dict.get(...)` returns the value of a key if it is set. The default parameter (the second parameter) only returns a default value **if the key does not exist**. Therefore, if the key `gen_metadata` is set in `kwargs`, and is set to `None`, then `kwargs.get("gen_metadata", [])` will return `None` and **not** an empty list (`[]`).

horde/classes/stable/processing_generation.py

@@ -79,7 +79,8 @@ def log_aborted_generation(self):
 
     def set_generation(self, generation, things_per_sec, **kwargs):
         state = kwargs.get("state", "ok")
-        for metadata in kwargs.get("gen_metadata", []):
+        gen_metadata = kwargs.get("gen_metadata", []) or []
+        for metadata in gen_metadata:
             if metadata.get("value") == "csam":
                 state = "csam"
             else: