adjust if statement and update comment as per pr feedback

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/components/structures/RoomSubList.js

@@ -335,9 +335,9 @@ const RoomSubList = React.createClass({
         const TruncatedList = sdk.getComponent('elements.TruncatedList');
 
         let content;
-        if (this.state.sortedList.length === 0) {
-            // check if emptyContent is defined, if falsey then don't show an empty sublist even without searchFilter
-            if (!this.props.searchFilter && this.props.extraTiles.length === 0 && this.props.emptyContent) {
+        if (this.state.sortedList.length === 0 && this.props.extraTiles.length === 0) {
+            // if no search filter is applied and there is a placeholder defined then show it, otherwise show nothing
+            if (!this.props.searchFilter && this.props.emptyContent) {
                 content = this.props.emptyContent;
             } else {
                 // don't show an empty sublist