feat: limit environment-variable json parsing to lists

freqtrade/configuration/environment_vars.py

@@ -1,8 +1,9 @@
-import json
 import logging
 import os
 from typing import Any
 
+import rapidjson
+
 from freqtrade.constants import ENV_VAR_PREFIX
 from freqtrade.misc import deep_merge_dicts
 
@@ -23,8 +24,11 @@ def _get_var_typed(val):
                 return False
             # try to convert from json
             try:
-                return json.loads(val)
-            except json.decoder.JSONDecodeError:
+                value = rapidjson.loads(val)
+                # Limited to lists for now
+                if isinstance(value, list):
+                    return value
+            except rapidjson.JSONDecodeError:
                 pass
     # keep as string
     return val