Revert "Update beat-tick.ts"

This reverts commit 430a142ff83abe8ae60d43fb10c943ec6a03f593.

src/views/tempo-practice/beat-tick.ts

@@ -85,7 +85,7 @@ export const handleStartBeat = async () => {
       const part = setting.scorePart[i][j];
       const params = {
         ...part,
-        ...beatDesc[part.index + 1]
+        ...beatDesc[part.index - 1]
       };
       // console.log(params);
       const single16th = beatData.beatLengthInMilliseconds;