fix issue with empty cat

appinfo/info.xml

@@ -15,7 +15,7 @@ You can report a bug or request a feature by opening an issue.
 ]]></description>
     <licence>agpl</licence>
     <author mail="contact@deblan.fr" homepage="https://www.deblan.io/">Simon Vieille</author>
-    <version>1.8.0-rc1</version>
+    <version>1.8.0-rc2</version>
     <namespace>SideMenu</namespace>
     <category>customization</category>
     <website>https://gitnet.fr/deblan/side_menu</website>

lib/Controller/NavController.php

@@ -188,8 +188,12 @@ class NavController extends Controller
         }
 
         foreach ($items as $category => $value) {
+            if (empty($items[$category]['apps'])) {
+                unset($items[$category]);
+            } else {
                 ksort($items[$category]['apps']);
             }
+        }
 
         usort($items, function ($a, $b) {
             return ($a['name'] < $b['name']) ? -1 : 1;