Editor: Fix React unknown props warnings in EditorAuthor wrapper (Aut…

…omattic#13467)

* Editor: Fix React unknown props warnings in EditorAuthor wrapper

* Editor: Use a ternary for EditorAuthor wrapper props

client/post-editor/editor-author/index.jsx

@@ -41,10 +41,17 @@ export class EditorAuthor extends Component {
 		const name = author.display_name || author.name;
 		const Wrapper = this.userCanAssignAuthor() ? AuthorSelector : 'div';
 		const popoverPosition = touchDetect.hasTouch() ? 'bottom right' : 'bottom left';
+		const wrapperProps = this.userCanAssignAuthor()
+			? {
+				siteId: post.site_ID,
+				onSelect: this.onSelect,
+				popoverPosition,
+			}
+			: {};
 
 		return (
 			<div className="editor-author">
-				<Wrapper siteId={ post.site_ID } onSelect={ this.onSelect } popoverPosition={ popoverPosition }>
+				<Wrapper { ...wrapperProps }>
 					<Gravatar size={ 26 } user={ author } />
 					<span className="editor-author__name">
 							{ translate( 'by %(name)s', { args: { name: name } } ) }