proxy depends on exact sshpass location

When connecting to the hass-proxy the proxy depends on sshpass located in /usr/bin, however on systems with sshpass located in /usr/local/bin (or other place outside default path) it fails with:

Upon execvpe /usr/bin/sshpass ['sshpass', '-p', '{"device_token": "w", "remote_port": x, "remote": "y", "pass": "test"}', 'ssh', '-o', 'UserKnownHostsFile=/dev/null', '-o', 'StrictHostKeyChecking=no', '-o', 'LogLevel=error', '-p', '10014', 'root@haas-app.nic.cz'] in environment id Z
:Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/Twisted-17.9.0-py2.7-freebsd-11.1-RELEASE-p1-amd64.egg/twisted/internet/process.py", line 445, in _fork
    environment)
  File "/usr/local/lib/python2.7/site-packages/Twisted-17.9.0-py2.7-freebsd-11.1-RELEASE-p1-amd64.egg/twisted/internet/process.py", line 523, in _execChild
    os.execvpe(executable, args, environment)
  File "/usr/local/lib/python2.7/os.py", line 355, in execvpe
    _execvpe(file, args, env)
  File "/usr/local/lib/python2.7/os.py", line 370, in _execvpe
    func(file, *argrest)
OSError: [Errno 2] No such file or directory