[gui] Fix to handle MCLAnalyser change: mac_search is a generator now

gui/cadbiom_gui/gt_gui/chart_checker/chart_checker_controler.py

@@ -367,8 +367,8 @@ class OccurenceForm(object):
         if ask:
             query = MCLSimpleQuery(self.start_prop,
                                    self.inv_prop, self.property)
-            mac_list = self.mcla.mac_search(query, self.max_step)
-            if len(mac_list)==0 :
+            mac_list = tuple(self.mcla.mac_search(query, self.max_step))
+            if not mac_list:
                 ok_warn("The solver could not find a MAC," +
                         "\n you should refine your query")
             else :