Fix themes/night.css for iOS browsers

Somehow the image filters order matters for iOS browsers (Chrome, Safari), so
grayscale filter is not applied if -webkit-filter is not the last filter in
list.

themes/night.css

@@ -135,9 +135,9 @@ body#ttrssMain .cdm img.tinyFeedIcon,
 body#ttrssMain .cdm .cdmFooter img,
 body#ttrssMain #feedTree img,
 body#ttrssMain .postContent img {
+	filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale"); // firefox lol
 	filter: grayscale(1);
 	-webkit-filter: grayscale(1);
-	filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale"); // firefox lol
 }
 
 body#ttrssMain .hl img.hlScorePic {