APNGでもMIME typeはimage/pngにするように (#5100)

* APNGでもMIME typeはimage/pngにするように

* Revert "APNGでもMIME typeはimage/pngにするように"

This reverts commit e579eb2bf4.

* APNGはファイル送信時のみimage/pngにするように

src/services/drive/add-file.ts

@@ -207,6 +207,8 @@ export async function generateAlts(path: string, type: string, generateWeb: bool
  * Upload to ObjectStorage
  */
 async function upload(key: string, stream: fs.ReadStream | Buffer, type: string, filename?: string) {
+	if (type === 'image/apng') type = 'image/png';
+
 	const meta = await fetchMeta();
 
 	const minio = new Minio.Client({

src/services/drive/image-processor.ts

@@ -97,6 +97,6 @@ export async function convertToApng(path: string): Promise<IImage> {
 	return {
 		data,
 		ext: 'apng',
-		type: 'image/vnd.mozilla.apng'
+		type: 'image/apng'
 	};
 }