Fixed onBlur being called when not given as a prop (#5024)

webapp/components/suggestion/suggestion_box.jsx

@@ -64,8 +64,11 @@ export default class SuggestionBox extends React.Component {
             // Delay this slightly so that we don't clear the suggestions before we run click handlers on SuggestionList
             GlobalActions.emitClearSuggestions(this.suggestionId);
         }, 100);
+
+        if (this.props.onBlur) {
             this.props.onBlur();
         }
+    }
 
     handleChange(e) {
         const textbox = this.getTextbox();