Make this work in preact.

Without key prop the input element unmounted and remounted after input changed, and the "onblur" handler make the panel dismissed soon.

src/Select.js

@@ -806,7 +806,7 @@ class Select extends React.Component {
 			);
 		}
 		return (
-			<div className={ className }>
+			<div className={ className } key="input-wrap">
 				<input {...inputProps} />
 			</div>
 		);