google login: use google mail address as login

No need to use a opaque user id. If we use mail address, to enable
google login for an existing user, we just have to "create google login
with email address and validate google login".

bt5/erp5_oauth_google_login/ExtensionTemplateItem/portal_components/extension.erp5.GoogleLoginUtility.py

@@ -53,5 +53,5 @@ def getUserId(access_token):
     socket.setdefaulttimeout(timeout)
 
   if google_entry is not None:
-    return google_entry['id'].encode('utf-8')
+    return google_entry['email'].encode('utf-8')
   return None
\ No newline at end of file

product/ERP5Security/ERP5ExternalOauth2ExtractionPlugin.py

@@ -163,7 +163,7 @@ class ERP5ExternalOauth2ExtractionPlugin:
     except KeyError:
       user_entry = self.getUserEntry(token)
       if user_entry is not None:
-        user = user_entry["reference"] = user_dict["login"]
+        user = user_entry["reference"]
 
     if user is None:
       # fallback to default way
@@ -263,14 +263,12 @@ class ERP5GoogleExtractionPlugin(ERP5ExternalOauth2ExtractionPlugin, BasePlugin)
     user_entry = {}
     if google_entry is not None:
       # sanitise value
-      try:
       for k in (('first_name', 'given_name'),
             ('last_name', 'family_name'),
-            ('email', 'email')):
+            ('email', 'email'),
+            ('reference', 'email'),):
         value = google_entry[k[1]].encode('utf-8')
         user_entry[k[0]] = value
-      except KeyError:
-        user_entry = None
     return user_entry
 
 #List implementation of class