CSS: Prevent collapsible fieldset headings in form to be selected on open

public/css/icinga/forms.less

@@ -43,7 +43,14 @@ form.icinga-form {
     }
 
     &:not(:last-of-type) .collapsible-control {
-      border-bottom: 1px solid @gray-light
+      border-bottom: 1px solid @gray-light;
+      cursor: default;
+      -webkit-touch-callout: none;
+      -webkit-user-select: none;
+      -khtml-user-select: none;
+      -moz-user-select: none;
+      -ms-user-select: none;
+      user-select: none;
     }
 
     .collapsed .collapsible-control {
@@ -63,8 +70,8 @@ form.icinga-form {
     }
 
     &.collapsed .collapsible-control:after {
-      /*content: "\e87b";*/
-      content: "\e87a";
+      content: "\e87b";
+      /*content: "\e87a";*/
     }
 
     .permission-heading {