fix getDefaultProps mixup

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/components/views/rooms/EventTile.js

@@ -155,9 +155,11 @@ module.exports = withMatrixClient(React.createClass({
         isTwelveHour: PropTypes.bool,
     },
 
-    defaultProps: {
-        // no-op function because onWidgetLoad is optional yet some subcomponents assume its existence
+    getDefaultProps: function() {
+        return {
+            // no-op function because onWidgetLoad is optional yet some sub-components assume its existence
             onWidgetLoad: function() {},
+        };
     },
 
     getInitialState: function() {