scripts/vagrant: Fix check for openstack_network

Previous check was always returning true forcing vagrant to add
additional net device to each VM with the same local ip address.
This interface is not needed by vagrant for communicating with
most of the VMs so make sure it's added for the openstack tests
only.

Change-Id: I64092d5c113d3b5f4575f83db640bf5dd40d4bf8
Signed-off-by: Michal Berger <michalx.berger@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/4542
Reviewed-by: Mellanox Build Bot
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

scripts/vagrant/Vagrantfile

@@ -310,7 +310,7 @@ Vagrant.configure(2) do |config|
   config.vm.synced_folder '.', '/vagrant', disabled: true
 
   # Add network interface for openstack tests
-  if openstack_network
+  if openstack_network == "1"
     config.vm.network "private_network", ip: "10.0.2.15"
   end
   # Copy in the .gitconfig if it exists