zoom quality subpar to gallery/leafpic

[KraXen72]

when i zoom into an image, images are lower quality than if zoomed in in default gallery/Leafpic revived.

i think stingle only initially scales photo to fit device width so when i zoom in, the quality is way worse than if it loaded the whole original picture. i have some pictures in 4K/8K and the quality drop is noticable.

i don't know how much it will help, but https://github.com/apcro/leafpicrevived gallery zooms images properly, so you can take a look at how they implemented it.

please fix this, thank you.

[alexamiryan]

Thanks for the report, will fix this.