指摘事項を修正

https://github.com/LangExt/LangExt/commit/6df6c8d2362fc928b0be24f5a22b73ccea0bd615#commitcomment-3937921
https://github.com/LangExt/LangExt/commit/6df6c8d2362fc928b0be24f5a22b73ccea0bd615#commitcomment-3937922