add bz950903 to 0.18.0 release notes

This was accidentally omitted since the patches didn't have
a documentation/whats-new/next/* file and the Bugzilla milestone was not
set correctly.

Change-Id: I0fbcd6de338572d4c85f89f2cf0f10979531832d
release notes for 0.18.1

Change-Id: Ic7dc1c63869ca2db9e72eee44172694015d8192c