mpd connection should be read from environment, not hardcoded localhost

[Tidux]

The MPD_HOST environment variable exists so client programs like mpDris2 can connect to daemons running on something other than localhost:6600. I have some systems where mpd is bound to a specific non-localhost IPv4 or IPv6 address in order to enable network control, and mpDris2 can't connect to these systems without manually editing the script. This is suboptimal.

[Mantas Mikulėnas]

Reading MPD_HOST from environment (and config file, and command line) has been supported since 2011:

mpDris2/mpDris2

Lines 583 to 594 in c8a764a

 if config.has_option('Connection', 'host'): 
     params['host'] = config.get('Connection', 'host') 
 if config.has_option('Connection', 'port'): 
     params['port'] = config.get('Connection', 'port') 
 if config.has_option('Connection', 'password'): 
     params['password'] = config.get('Connection', 'password') 
  
  
 if 'MPD_HOST' in os.environ: 
     params['host'] = os.environ['MPD_HOST'] 
 if 'MPD_PORT' in os.environ: 
     params['port'] = os.environ['MPD_PORT']