Fix inability to disable Skype/Delicious/Diigo

The view was missing a check for whether these services are enabled, so
they were showing even when disabled in Account Settings.

Test Plan:
 * First enable Skype, Delicious, and Diigo in Account Settings
 * Confirm that they both show up in the user's Profile Settings
 * Disable Skype in Account Settings
 * Confirm that Skype no longer shows up in Profile Settings
 * Repeat last 2 steps with Delicious and Diigo
Merge pull request #349 from sfu/fix-disable_services

Fix inability to disable Skype/Delicious/Diigo