closes https://github.com/NodeBB/nodebb-theme-persona/issues/79

public/language/en_GB/category.json

@@ -8,6 +8,7 @@
 
 	"browsing": "browsing",
 	"no_replies": "No one has replied",
+	"no_new_posts": "No new posts.",
 
 	"share_this_category": "Share this category",
 	"watch": "Watch",

public/src/app.js

@@ -381,7 +381,8 @@ app.cacheBuster = null;
 	};
 
 	function createHeaderTooltips() {
-		if (utils.findBootstrapEnvironment() === 'xs') {
+		var env = utils.findBootstrapEnvironment();
+		if (env === 'xs' || env === 'sm') {
 			return;
 		}
 		$('#header-menu li a[title]').each(function() {