Fix used same variable name triggered reading var before setting

jsoncache/ApplicationCache.py

@@ -92,14 +92,14 @@ class ApplicationCache():
 
     def cache_anything(self, key_prefix: str = None, max_age: int = None, packer = IDENTITY, unpacker = IDENTITY):
         def decorator(fun):
-            key_prefix = key_prefix or fun.__name__
+            cache_prefix = key_prefix or fun.__name__
             @wraps(fun)
             def decorated(*args, no_cache: bool = False, cache_no_lookup: bool = False, cache_no_store: bool = False, **kwargs):
                 cache_no_lookup = no_cache or cache_no_lookup
                 cache_no_store = no_cache or cache_no_store
                 no_cache_key = cache_no_lookup and cache_no_store
                 if not no_cache_key:
-                    cache_key = self.gen_key(key_prefix, args, kwargs)
+                    cache_key = self.gen_key(cache_prefix, args, kwargs)
                 if not cache_no_lookup:
                     cached_data = self.load(key=cache_key, max_age=max_age)
                     if cached_data is not None: