refactor: reduce code duplicity around network entity ID detection

clouds/g2/ostrava/general/commandline/cmdline-demo.sh

@@ -92,12 +92,11 @@ openstack security group rule create --egress --proto tcp --remote-ip 0.0.0.0/0
 if [ "${project_type}" == "group" ]; then
   log_section_keypress "Create cloud private network and subnet, so far isolated (CIDR:${SUBNET_CIDR})"
   openstack network create "${NETWORK_NAME}"
-  NETWORK_ID=$(openstack network show "${NETWORK_NAME}" -f value -c id)
   openstack subnet create "${SUBNET_NAME}" --network "${NETWORK_ID}" --subnet-range "${SUBNET_CIDR}" --dns-nameserver 8.8.4.4 --dns-nameserver 8.8.8.8
 else
   log_section_keypress "Re-use existing network (${NETWORK_NAME}) and subnet (${SUBNET_NAME})"
-  NETWORK_ID=$(openstack network show "${NETWORK_NAME}" -f value -c id)
 fi
+NETWORK_ID=$(openstack network show "${NETWORK_NAME}" -f value -c id)
 # ---------------------------------------------------------------------------
 
 if [ "${EXTRA_VOLUME_SIZE_GB}" -gt 0 ]; then