Remove unused SUPPORT_NODE variable

The SUPPORT_NODE variable was missed during a refactoring of
bootstrap.sh and is now unused. Remove it.

TrivialFix

Change-Id: I10ab4368b383dbb620916f70c368153403944001

dev/vagrant/bootstrap.sh

@@ -16,10 +16,8 @@ export https_proxy=
 if [ "$MODE" = 'aio' ]; then
     # Run registry on port 4000 since it may collide with keystone when doing AIO
     REGISTRY_PORT=4000
-    SUPPORT_NODE=operator
 else
     REGISTRY_PORT=5000
-    SUPPORT_NODE=support01
 fi
 REGISTRY_URL="operator.local"
 REGISTRY=${REGISTRY_URL}:${REGISTRY_PORT}