Prevent RequestBody from accessing a media type that ceased to exist

src/core/components/content-type.jsx

@@ -27,6 +27,16 @@ export default class ContentType extends React.Component {
     }
   }
 
+  componentWillReceiveProps(nextProps) {
+    if(!nextProps.contentTypes || !nextProps.contentTypes.size) {
+      return
+    }
+
+    if(!nextProps.contentTypes.includes(nextProps.value)) {
+      nextProps.onChange(nextProps.contentTypes.first())
+    }
+  }
+
   onChangeWrapper = e => this.props.onChange(e.target.value)
 
   render() {