ssh_gateway_command not passed to Netcat command for testing remote port

Description of Issue

With the update in PR's #48062 and #48199 by @icy, the custom command is not getting passed to the port test on line 810.

Setup

....
ssh_gateway: gateway.host.com
ssh_gateway_user: saltproxyuser
ssh_gateway_key: /key
ssh_gateway_command: "-W %h:%p"

gateway:
   ssh_gateway: gateway.host.com
   ssh_gateway_user: saltproxyuser
   ssh_gateway_key: /key
   ssh_gateway_command: "-W %h:%p"
...

Steps to Reproduce Issue

sudo salt-cloud -ym newHostFile -l debug

[DEBUG   ] Retrying connection to host 123.45.67.89 on port 22 via gateway gateway.host.com on port 22. (try 13)
[DEBUG   ] Child Forked! PID: 7498  STDOUT_FD: 7  STDERR_FD: 12
[DEBUG   ] Terminal Command: /bin/sh -c ssh -oStrictHostKeyChecking=no -oUserKnownHostsFile=/dev/null -oControlPath=none -oPasswordAuthentication=no -oChallengeResponseAuthentication=no -oPubkeyAuthentication=yes -oIdentitiesOnly=yes -oKbdInteractiveAuthentication=no -i /key saltproxyuser@gateway.host.com -p 22 'nc -z -w5 -q0 123.45.67.89'
[DEBUG   ] Warning: Permanently added 'gateway.host.com' (ECDSA) to the list of known hosts.
nc: invalid option -- 'q'

Versions Report

Salt Version:
           Salt: 2019.2.2
 
Dependency Versions:
           cffi: 1.5.2
       cherrypy: Not Installed
       dateutil: 2.4.2
      docker-py: Not Installed
          gitdb: 0.6.4
      gitpython: 1.0.1
          ioflo: Not Installed
         Jinja2: 2.8
        libgit2: Not Installed
        libnacl: Not Installed
       M2Crypto: Not Installed
           Mako: 1.0.3
   msgpack-pure: Not Installed
 msgpack-python: 0.4.6
   mysql-python: Not Installed
      pycparser: 2.14
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: Not Installed
         Python: 2.7.12 (default, Oct  8 2019, 14:14:10)
   python-gnupg: 0.3.8
         PyYAML: 3.11
          PyZMQ: 15.2.0
           RAET: Not Installed
          smmap: 0.9.0
        timelib: Not Installed
        Tornado: 4.2.1
            ZMQ: 4.1.4
 
System Versions:
           dist: Ubuntu 16.04 xenial
         locale: UTF-8
        machine: x86_64
        release: 4.4.0-150-generic
         system: Linux
        version: Ubuntu 16.04 xenial

Start at salt/utils/cloud.py around line 810 and reproduce with the provided salt-cloud command and gateway configuration. Trace the remote port-test command construction and verify that ssh_gateway_command is included in the resulting Netcat invocation; the debug output should no longer omit the configured gateway command.