Hide main Responses ContentType picker for OAS3

src/core/components/responses.jsx

@@ -39,13 +39,13 @@ export default class Responses extends React.Component {
       <div className="responses-wrapper">
         <div className="opblock-section-header">
           <h4>Responses</h4>
-            <label>
+            { specSelectors.isOAS3() ? null : <label>
               <span>Response content type</span>
               <ContentType value={producesValue}
                          onChange={this.onChangeProducesWrapper}
                          contentTypes={produces}
                          className="execute-content-type"/>
-                     </label>
+                     </label> }
         </div>
         <div className="responses-inner">
           {