Add a check that values is not empty

src/sia/dependencies/query_params.py

@@ -26,7 +26,7 @@ async def get_sia_params_dependency(
             post_params_ddict[key].append(value)
 
         post_params = {
-            key: (values[0] if key in SINGLE_PARAMS else values)
+            key: (values[0] if key in SINGLE_PARAMS and values else values)
             for key, values in post_params_ddict.items()
         }
         params = SIAQueryParams.from_dict(post_params)