[FIX] awesome_owl: Fixed error when counter doesnt have a onChange attribute

Author: Backendt

awesome_owl/static/src/counter/counter.js

@@ -14,6 +14,8 @@ export class Counter extends Component {
 
     increment() {
         this.state.value++;
-        this.props.onChange();
+        if(this.props.onChange) {
+            this.props.onChange();
+        }
     }
 }