fix: gutter tooltip class fix (#5211)

Author: akoreman

src/mouse/default_gutter_handler.js

@@ -203,18 +203,19 @@ class GutterTooltip extends Tooltip {
         var tooltipContent = [].concat(annotationMessages.error, annotationMessages.warning, annotationMessages.info).join("<br>");
 
         this.setHtml(tooltipContent);
-        this.setClassName("ace_gutter-tooltip");
         this.$element.setAttribute("aria-live", "polite");
 
         if (!this.isOpen) {
             this.setTheme(this.editor.renderer.theme);
+            this.setClassName("ace_gutter-tooltip");
         }
 
         this.show();
         this.editor._signal("showGutterTooltip", this);
     }
 
     hideTooltip() {
+        this.$element.removeAttribute("aria-live");
         this.hide();
         this.editor._signal("hideGutterTooltip", this);
     }