subprocess.check_call(args, stdout=subprocess.DEVNULL while installing the theme on DragonFlyBSD

On DragonFlyBSD 6.1 :

```
root@marietto:/home/marietto/Desktop/Chicago95 # ./installer.py

Error creating proxy: The connection is closed (g-io-error-quark, 18)
Installer running from: /home/marietto/Desktop/Chicago95
[PANEL] Warning: xfce4-panel-profiles not installed, manual panel installation required. See INSTALL.md
Installing Chicago 95 with the following options:
Components:
Theme: True
Icons: True
Cursors: True
Background: True
Sounds: True
Fonts: True
Customizations:
Thunar Graphics: True
Change Terminal Colors: True
Set Bash Prompt: True
Set zsh promt/theme: False
Customize Panel: False
Installing Chicago 95
Enabling Theme in XFCE4
Changing xfconf setting xsettings//Net/ThemeName to Chicago95
Failed to init libxfconf: The connection is closed.
Changing xfconf setting xsettings//Net/ThemeName to Chicago95
Failed to init libxfconf: The connection is closed.
Traceback (most recent call last):
File "./installer.py", line 438, in xfconf_query
subprocess.check_call(args, stdout=subproroot@marietto:/home/marietto/Desktop/Chicago95 # ./installer.py

Error creating proxy: The connection is closed (g-io-error-quark, 18)
Installer running from: /home/marietto/Desktop/Chicago95
[PANEL] Warning: xfce4-panel-profiles not installed, manual panel installation required. See INSTALL.md
Installing Chicago 95 with the following options:
Components:
Theme: True
Icons: True
Cursors: True
Background: True
Sounds: True
Fonts: True
Customizations:
Thunar Graphics: True
Change Terminal Colors: True
Set Bash Prompt: True
Set zsh promt/theme: False
Customize Panel: False
Installing Chicago 95
Enabling Theme in XFCE4
Changing xfconf setting xsettings//Net/ThemeName to Chicago95
Failed to init libxfconf: The connection is closed.
Changing xfconf setting xsettings//Net/ThemeName to Chicago95
Failed to init libxfconf: The connection is closed.
Traceback (most recent call last):
File "./installer.py", line 438, in xfconf_query
subprocess.check_call(args, stdout=subprocess.DEVNULL)
File "/usr/local/lib/python3.8/subprocess.py", line 364, in check_call
raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '[b'/usr/local/bin/xfconf-query', '--channel', 'xsettings', '--property', '/Net/ThemeName', '--set', 'Chicago95']' returned non-zero exit status 1.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "./installer.py", line 259, in install
self.xfconf_query('xsettings', '/Net/ThemeName', "Chicago95")
File "./installer.py", line 450, in xfconf_query
subprocess.check_call(args, stdout=subprocess.DEVNULL)
File "/usr/local/lib/python3.8/subprocess.py", line 364, in check_call
raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '[b'/usr/local/bin/xfconf-query', '--channel', 'xsettings', '--property', '/Net/ThemeName', '--create', '--type', 'string', '--set', 'Chicago95']' returned non-zero exit status 1.cess.DEVNULL)
File "/usr/local/lib/python3.8/subprocess.py", line 364, in check_call
raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '[b'/usr/local/bin/xfconf-query', '--channel', 'xsettings', '--property', '/Net/ThemeName', '--set', 'Chicago95']' returned non-zero exit status 1.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "./installer.py", line 259, in install
self.xfconf_query('xsettings', '/Net/ThemeName', "Chicago95")
File "./installer.py", line 450, in xfconf_query
subprocess.check_call(args, stdout=subprocess.DEVNULL)
File "/usr/local/lib/python3.8/subprocess.py", line 364, in check_call
raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '[b'/usr/local/bin/xfconf-query', '--channel', 'xsettings', '--property', '/Net/ThemeName', '--create', '--type', 'string', '--set', 'Chicago95']' returned non-zero exit status 1.
```