[Glitch] Fix JavaScript console error on Getting Started column

Port ffe735344b to glitch-soc

Co-authored-by: Ilias Tsangaris <iliastsangaris@gmail.com>

Co-authored-by: Ilias Tsangaris <iliastsangaris@gmail.com>
Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/components/column_header.js

@@ -63,7 +63,7 @@ class ColumnHeader extends React.PureComponent {
   }
 
   handleTitleClick = () => {
-    this.props.onClick();
+    this.props.onClick?.();
   }
 
   handleMoveLeft = () => {