refactor(mpd): prefer debug over warn

src/modules/mpd.cpp

@@ -74,9 +74,13 @@ std::thread waybar::modules::MPD::event_listener() {
           dp.emit();
         }
       } catch (const std::exception& e) {
+        if (e.what() == "Connection to MPD closed") {
+          spdlog::debug("{}: {}", module_name_, e.what());
+        } else {
           spdlog::warn("{}: {}", module_name_, e.what());
         }
       }
+    }
   });
 }