yt-dlpのインストールに失敗することがある不具合を修正

src/main/java/com/sedmelluq/discord/lavaplayer/source/nico/NicoAudioSourceManager.java

@@ -107,7 +107,7 @@ public void updateYtDlp() {
             }
 
             log.info("Updating yt-dlp using {}.", pythonCommand);
-            Process process = runtime.exec(pythonCommand + " -m pip install -U --pre \"yt-dlp\"");
+            Process process = runtime.exec(pythonCommand + " -m pip install -U --pre yt-dlp");
             process.waitFor();
             process.destroy();
             log.info("yt-dlp update completed.");