allow to override default player

mpris-widget/init.lua

@@ -12,7 +12,7 @@ local wibox             = require("wibox")
 local gears             = require("gears")
 
 local playerctl = {
-    player_name = 'mpv',
+    player_name = nil,
 }
 
 function playerctl:set_player(name)
@@ -191,6 +191,8 @@ local function worker(user_args)
     local library_icon = args.library_icon or path_to_icons .. "/symbolic/places/folder-music-symbolic.svg"
     local popup_width  = args.popup_width or 300
 
+    playerctl.player_name = args.default_player or 'mpv'
+
     local icon = wibox.widget {
         widget = wibox.widget.imagebox,
         image = play_icon