help: "activity log" is now "inbox" (bug #863262)

Change-Id: I6363ae6bba940b89d8d3bc009b6fb0f706216f47
Signed-off-by: Francois Marier <francois@catalyst.net.nz>

htdocs/lang/en.utf8/help/pages/account/notifications.html

 <h3>Notifications</h3>
 <p>You may select how you receive notifications for each activity type.</p>
 <h4>Notification Types</h4>
-<p><strong>Activity Log:</strong> your notifications area will display a list of activity notifications received.</p>
+<p><strong>Inbox:</strong> your notifications area will display a list of activity notifications received.</p>
 <p><strong>Email:</strong> your primary email address will receive an email each time the activity occurs.</p>
 <p><strong>Email digest:</strong> your primary email address will receive an email each day with a list of the last 24 hours’ activities</p>
 <p><strong>Note:</strong> If you select either email option all activities will also be recorded in your notifications log as they happen. They will all be marked as already read. These notifications automatically expire and are removed from your log after 60 days.</p>