Fix react warnings and part of backstage (#4706)

webapp/components/webrtc/components/webrtc_header.jsx

@@ -96,5 +96,5 @@ export default class WebrtcHeader extends React.Component {
 WebrtcHeader.propTypes = {
     username: React.PropTypes.string.isRequired,
     onClose: React.PropTypes.func.isRequired,
-    toggleSize: React.PropTypes.function
+    toggleSize: React.PropTypes.func
 };

webapp/components/webrtc/webrtc_controller.jsx

@@ -1218,5 +1218,5 @@ WebrtcController.propTypes = {
     userId: React.PropTypes.string.isRequired,
     isCaller: React.PropTypes.bool.isRequired,
     expanded: React.PropTypes.bool.isRequired,
-    toggleSize: React.PropTypes.function
-};
+    toggleSize: React.PropTypes.func
+};