Don't bolden navbar's sub.

misago/static/misago/admin/css/misago/header.less

@@ -21,6 +21,8 @@
 
     .main, .sub {
       float: left;
+
+      font-weight: normal;
     }
 
     .main {

misago/static/misago/admin/css/style.css

@@ -6443,6 +6443,7 @@ body {
 .page-header h1 .main,
 .page-header h1 .sub {
   float: left;
+  font-weight: normal;
 }
 .page-header h1 .main a {
   color: #444444;