fix(flat-components): remove horizontal scrollbar in chat users (netless-io#1787)

Author: hyrious

packages/flat-components/src/components/ChatPanel/ChatUsers/style.less

@@ -44,6 +44,7 @@
     left: 0;
     width: 100%;
     height: 100%;
+    overflow-x: hidden;
     overflow-y: auto;
     padding: 0 12px;