Follow-up 73ec3a331: fix fatal when no cross-wiki results are found
Follow-up 73ec3a331: fix fatal when no cross-wiki results are found

If we don't initialize $results, getForeignNotifications() will return
null, and this will cause a fatal when trying to += it into an array.

Change-Id: Ibb868cbf0b52ff2de41c5be82c9605801e51ffae

wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo