Only rendering the emoji picker when it's needed

If not done so the whole channel select render will take an eternity

shared/js/ui/react-elements/ChatBox.tsx

@@ -59,7 +59,9 @@ const EmojiButton = (props: { events: Registry<ChatBoxEvents> }) => {
                 <img alt={""} src={"img/smiley-smile.svg"} />
             </div>
             <div className={cssStyle.picker} style={{ display: shown ? undefined : "none" }}>
+                {!shown ? undefined :
                     <Picker
+                        key={"picker"}
                         set={"twitter"}
                         theme={"light"}
                         showPreview={true}
@@ -74,6 +76,7 @@ const EmojiButton = (props: { events: Registry<ChatBoxEvents> }) => {
                             }
                         }}
                     />
+                }
             </div>
         </div>
     );