[Fix] Remove all Scenarios, catch empty SMILES, prevent default Package delete (#134)

Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Reviewed-on: enviPath/enviPy#134

templates/modals/objects/generic_set_scenario_modal.html

@@ -64,6 +64,9 @@
 
             $('#set_scenario_modal_form_submit').on('click', function (e) {
                 e.preventDefault();
+                if ($('##scenario-select').val().length == 0) {
+                    $('##scenario-select').val([''])
+                }
                 $('#set_scenario_modal_form').submit();
             });
         });