erp5_core: Don't enable login buttons if the connector isnt configured

  If the login button isnt suppose to work, dont display it.

product/ERP5/bootstrap/erp5_core/SkinTemplateItem/portal_skins/erp5_core/ERP5Site_getAvailableOAuthLoginList.py

@@ -3,10 +3,14 @@ oauth_login_list = []
 portal_skin = context.getPortalObject().portal_skins
 
 if getattr(portal_skin, "erp5_oauth_google_login", None) is not None:
-  oauth_login_list.append("google")
+  connector = context.ERP5Site_getGoogleConnector()
+  if connector and connector[0].getClientId() is not None:
+    oauth_login_list.append("google")
 
 if getattr(portal_skin, "erp5_oauth_facebook_login", None) is not None:
-  oauth_login_list.append("facebook")
+  connector = context.ERP5Site_getFacebookConnector()
+  if connector and connector[0].getClientId() is not None:
+    oauth_login_list.append("facebook")
 
 if getattr(portal_skin, "erp5_openid_connect_client", None) is not None:
   oauth_login_list.append("openidconnect")

product/ERP5/bootstrap/erp5_core/SkinTemplateItem/portal_skins/erp5_core/ERP5Site_getAvailableOAuthLoginList.xml

@@ -52,6 +52,14 @@
             <key> <string>_params</string> </key>
             <value> <string></string> </value>
         </item>
+        <item>
+            <key> <string>_proxy_roles</string> </key>
+            <value>
+              <tuple>
+                <string>Manager</string>
+              </tuple>
+            </value>
+        </item>
         <item>
             <key> <string>id</string> </key>
             <value> <string>ERP5Site_getAvailableOAuthLoginList</string> </value>