Fix drag the start/end ruby index will throw the exception.#2318

andy840119 merged 1 commit intokaraoke-dev:masterkaraoke-dev/karaoke:masterfrom

andy840119:fix-drag-scale-selection-handler-might-cause-exceptionandy840119/karaoke:fix-drag-scale-selection-handler-might-cause-exceptionCopy head branch name to clipboard