Do not subscribe portal_alarms unconditionally.

In case of erp5_core business template update this code is called (with update=True argument)
and thus it will effectively override previous portal_alarms' state which
is wrong as no "general purpose" code should overwrite potential
developer configuration.
Tests passing at https://nexedi.erp5.net/test_result_module/20200324-3BC4D696 thus merging right away.

See merge request !1086

product/ERP5/ERP5Site.py

@@ -2350,9 +2350,6 @@ class ERP5Generator(PortalGenerator):
 
     self.setupTools(p, **kw)
 
-    # subscribe portal_alarms
-    p.portal_alarms.subscribe()
-
     if not p.hasObject('MailHost'):
       self.setupMailHost(p)
 
@@ -2385,6 +2382,8 @@ class ERP5Generator(PortalGenerator):
       self.setupWorkflow(p)
       self.setupERP5Core(p,**kw)
       self.setupERP5Promise(p,**kw)
+      # subscribe portal_alarms
+      p.portal_alarms.subscribe()
 
     # Make sure the cache is initialized
     p.portal_caches.updateCache()
@@ -2421,7 +2420,6 @@ class ERP5Generator(PortalGenerator):
       template_tool.updateRepositoryBusinessTemplateList(repository.split())
       template_tool.installBusinessTemplateListFromRepository(
           ['erp5_promise'], activate=True, install_dependency=True)
-      p.portal_alarms.subscribe()
 
 
 # Zope offers no mechanism to extend AppInitializer so let's monkey-patch.