Fixed a grep call.

23.Initialize_APT/0_setup.sh

@@ -22,7 +22,7 @@ apt-get install -y aptitude apt-transport-https
 #apt-get dist-upgrade -y
 
 # modify sources.list to use ubicast cache
-if ( ! grep ${APT_CACHE_HOST} /etc/apt/sources.list ); then
+if ( ! grep "${APT_CACHE_HOST}" /etc/apt/sources.list >/dev/null ); then
 	echo "Updating sources.list to use cache ${APT_CACHE_HOST}."
 	sed -i "s@http://@http://${APT_CACHE_HOST}/@" /etc/apt/sources.list
 fi