Return server version from znc --version

    CLI Example:

    .. code-block:: bash

        salt '*' znc.version

def version():
    '''
    Return server version from znc --version

    CLI Example:

    .. code-block:: bash

        salt '*' znc.version
    '''
    cmd = ['znc', '--version']
    out = __salt__['cmd.run'](cmd, python_shell=False).splitlines()
    ret = out[0].split(' - ')
    return ret[0]