Fixing recc.engine bug - empty dictionaries in kpis

app/api/dexi.py

@@ -360,7 +360,7 @@ def plus_one_kpi_change_generator(json_file: Dict, step_size, analysis_limit):
         was_it_increased_flag = False
         if k == 'simulation_id':
             continue
-        if isinstance(v, dict):
+        if isinstance(v, dict) and len(v) != 0:
             json_file[k] = plus_one_kpi_change_generator(v, step_size, analysis_limit)
             for i in json_file[k]:
                 json_file[k] = i[0]