added message to admin panel if no themes are found

public/css/admin.less

@@ -85,6 +85,10 @@
 			&:hover {
 				background-color: rgba(128, 128, 128, 0.2);
 			}
+
+			&.no-themes {
+				font-style: italic;
+			}
 		}
 	}
 

public/src/forum/admin/themes.js

@@ -86,6 +86,7 @@ var nodebb_admin = (function(nodebb_admin) {
 			themeFrag = document.createDocumentFragment(),
 			liEl = document.createElement('li');
 
+		if (themes.length > 0) {
 			for(var x=0,numThemes=themes.length;x<numThemes;x++) {
 				liEl.setAttribute('data-theme', themes[x].id);
 				liEl.setAttribute('data-css', themes[x].src);
@@ -104,6 +105,12 @@ var nodebb_admin = (function(nodebb_admin) {
 									'<div class="clear">';
 				themeFrag.appendChild(liEl.cloneNode(true));
 			}
+		} else {
+			// No themes found
+			liEl.className = 'no-themes';
+			liEl.innerHTML = 'No installed themes found';
+			themeFrag.appendChild(liEl);
+		}
 
 		instListEl.innerHTML = '';
 		instListEl.appendChild(themeFrag);