Add missing propType

Signed-off-by: marcin mikołajczak <git@mkljczk.pl>

app/soapbox/features/compose/components/search_results.js

@@ -19,6 +19,7 @@ export default class SearchResults extends ImmutablePureComponent {
     submitted: PropTypes.bool,
     expandSearch: PropTypes.func.isRequired,
     selectedFilter: PropTypes.string.isRequired,
+    selectFilter: PropTypes.func.isRequired,
   };
 
   handleLoadMore = () => this.props.expandSearch(this.props.selectedFilter);