Revert "cwebpのjpeg_likeなオプションと同じくquality設定してprocessいれる"

This reverts commit e92b2c0.

webp.go

@@ -51,12 +51,7 @@ func convWebp(src io.Reader) (*bytes.Buffer, error) {
 		return nil, err
 	}
 
-	processed, err := bimg.NewImage(img).Process(bimg.Options{Quality: 75})
-	if err != nil {
-		return nil, err
-	}
-
-	webpImg, err := bimg.NewImage(processed).Convert(bimg.WEBP)
+	webpImg, err := bimg.NewImage(img).Convert(bimg.WEBP)
 	if err != nil {
 		return nil, err
 	}