Update the plus sign char. for array Add buttons.

Author: n1k0

src/components/fields/ArrayField.js

@@ -388,7 +388,7 @@ function AddButton({onClick, disabled}) {
       <p className="col-xs-2 col-xs-offset-10 array-item-add text-right">
         <button type="button" className="btn btn-info col-xs-12"
                 tabIndex="-1" onClick={onClick}
-                disabled={disabled} style={{fontWeight: "bold"}}>＋</button>
+                disabled={disabled} style={{fontWeight: "bold"}}>➕</button>
       </p>
     </div>
   );