Silence usages of componentWillReceiveProps

For https://github.com/vector-im/riot-web/issues/12877

src/components/structures/auth/Login.js

@@ -134,7 +134,8 @@ export default createReactClass({
         this._unmounted = true;
     },
 
-    componentWillReceiveProps(newProps) {
+    // TODO: [REACT-WARNING] Replace with appropriate lifecycle event
+    UNSAFE_componentWillReceiveProps(newProps) {
         if (newProps.serverConfig.hsUrl === this.props.serverConfig.hsUrl &&
             newProps.serverConfig.isUrl === this.props.serverConfig.isUrl) return;