devstack-vm-gate-dev.sh: rename DEVSTACK_GATE_QUANTUM

The variable is called DEVSTACK_GATE_NEUTRON now.

Change-Id: Ib97fa1c86718d22f3883409a8ca826064bdeca38

devstack-vm-gate-dev.sh

@@ -16,7 +16,7 @@ export BUILD_NUMBER=42
 export GERRIT_CHANGE_NUMBER=1234
 export GERRIT_PATCHSET_NUMBER=1
 export DEVSTACK_GATE_TEMPEST=${DEVSTACK_GATE_TEMPEST:-0}
-export DEVSTACK_GATE_QUANTUM=${DEVSTACK_GATE_QUANTUM:-0}
+export DEVSTACK_GATE_NEUTRON=${DEVSTACK_GATE_NEUTRON:-0}
 export DEVSTACK_GATE_HEAT=${DEVSTACK_GATE_HEAT:-0}
 export DEVSTACK_GATE_GRENADE=${DEVSTACK_GATE_GRENADE:-""}
 EOF