Tell getops to parse -D flag on vcap_dev_setup

Change-Id: I7a03a59b818da94570da73149ac8dc3e1d5c932e

dev_setup/bin/vcap_dev_setup

@@ -28,7 +28,7 @@ fi
 
 APT_CONFIG="-o Acquire::http::No-Cache=True -o Acquire::BrokenProxy=true -o Acquire::Retries=3"
 
-while getopts "had:p:c:r:b:" OPTION
+while getopts "had:p:c:D:r:b:" OPTION
 do
   case $OPTION in
     h)