VNC/SPICE should listen on all interfaces

Until now, we only allowed VNC/SPICE console to listen on connections
coming from localhost. This however breaks "Desktop viewer" use case
where user wants to download a virt-viewer file to a client computer
and open a VNC/SPICE console connected to a remote VNC server.

Fixes cockpit-project#1078

src/scripts/install_machine.py

@@ -46,8 +46,8 @@ def get_graphics_capabilies(connection):
 
 def prepare_graphics_params(connection):
     graphics_config = {
-        'spice': {'listen': '127.0.0.1'},
-        'vnc': {'listen': '127.0.0.1'}
+        'spice': {'listen': '0.0.0.0'},
+        'vnc': {'listen': '0.0.0.0'}
     }
     try:
         # Configparser needs a default section
@@ -57,12 +57,12 @@ def prepare_graphics_params(connection):
         config = configparser.ConfigParser()
         config.read_string(config_string)
 
-        graphics_config['spice']['listen'] = config['dummy_section'].get('spice_listen', '127.0.0.1')
+        graphics_config['spice']['listen'] = config['dummy_section'].get('spice_listen', '0.0.0.0')
         spice_password = config['dummy_section'].get('spice_password', None)
         if spice_password is not None:
             graphics_config['spice']['password'] = spice_password
 
-        graphics_config['vnc']['listen'] = config['dummy_section'].get('vnc_listen', '127.0.0.1')
+        graphics_config['vnc']['listen'] = config['dummy_section'].get('vnc_listen', '0.0.0.0')
         vnc_password = config['dummy_section'].get('vnc_password', None)
         if vnc_password is not None:
             graphics_config['vnc']['password'] = vnc_password