erp5_core: decrease the activity priority value

Try to not accumulate too many activities

product/ERP5/bootstrap/erp5_core/MixinTemplateItem/portal_components/mixin.erp5.SimulableMixin.py

@@ -101,7 +101,11 @@ class SimulableMixin(Base):
         applied_rule = self._createRootAppliedRule()
         expand_root = applied_rule is not None
     activate_kw = {'tag': 'build:'+self.getPath(),
-     'priority': SIMULATION_PRIORITY
+     # Keep this value lower than the current priority
+     # to allow the full _updateSimulation
+     # to be finished before triggering new one
+     # and so, trying to not increase the number of activities
+     'priority': max(1, SIMULATION_PRIORITY-1)
     }
     if expand_root:
       applied_rule.expand(activate_kw=activate_kw)