fix: add descriptive message

coordinator/ProcessorSurveys.py

@@ -370,7 +370,7 @@ class ProcessorSurveys(Processor):
             origins_list = df_join["Origin"].unique()
             groups = {i:[i] for i in origins_list}
 
-            assert not np_any([k in origins_list for k in config['Survey']['Groups'].keys()])
+            assert not np_any([k in origins_list for k in config['Survey']['Groups'].keys()]), 'Group(s) defined in config already present in the survey data as origin'
 
             groups.update(config['Survey']['Groups'])