Revert "new 404"

Browsers don't like a video as a 404
This reverts commit eb7f8871ea.

static/error/404/404.conf

@@ -1,6 +1,6 @@
-error_page 403 =404 /dayman.mp4;
-error_page 404 /dayman.mp4;
-location = /dayman.mp4 {
+error_page 403 =404 /lain_404.gif;
+error_page 404 /lain_404.gif;
+location = /lain_404.gif {
         root /opt/pleroma/instance/static/static/error/404;
         internal;
         add_header Strict-Transport-Security "max-age=31536000; includeSubdomains; preload";