That's nice solution. But I needed to add !important to end of filter to make it work.
For userscript usage (with greasemonkey, tampermoney etc.):
// ==UserScript==
// @name lemmynsfw no blur
// @description lemmynsfw no blur
// @match https://lemmynsfw.com/
// @grant GM_addStyle
// @run-at document-start
// ==/UserScript==
GM_addStyle(`
.img-blur {
filter: none !important;
-webkit-filter: none !important;
-moz-filter: none !important;
-o-filter: none !important;
-ms-filter: none !important;
}
`);