make sure that the UI is installed from an OSM repo

Signed-off-by: Jeremy Mordkoff <jeremy.mordkoff@gmail.com>

jenkins/UI/install

@@ -101,6 +101,7 @@ apt-get install -y --allow-downgrades rw.tools-container-tools=${PLATFORM_VERSIO
 
 # now disable the RIFT OSM repo so that we'll get UI from
 # the OSM repos
+rm -f /etc/apt/sources.list.d/rift.list
 
 apt-get update
 apt-get install -y rw.ui-skyquake