increase border radius on navbar

docs/assets/css/bootstrap.css

@@ -3637,7 +3637,7 @@ input[type="button"].btn-block {
   background-image: linear-gradient(to bottom, #ffffff, #f2f2f2);
   background-repeat: repeat-x;
   border: 1px solid #d4d4d4;
-  border-radius: 4px;
+  border-radius: 6px;
   filter: progid:dximagetransform.microsoft.gradient(startColorstr='#ffffffff', endColorstr='#fff2f2f2', GradientType=0);
   -webkit-box-shadow: 0 1px 4px rgba(0, 0, 0, 0.065);
           box-shadow: 0 1px 4px rgba(0, 0, 0, 0.065);

less/navbar.less

@@ -14,7 +14,7 @@
   color: @navbarText;
   #gradient > .vertical(@navbarBackgroundHighlight, @navbarBackground);
   border: 1px solid @navbarBorder;
-  border-radius: 4px;
+  border-radius: 6px;
   .box-shadow(0 1px 4px rgba(0,0,0,.065));
 
   // Prevent floats from breaking the navbar