Fix exception while saving room settings

[bwindels]

I got the following exception while trying to save the room settings:

Uncaught TypeError: this.refs.url_preview_settings.saveSettings is not a function
    at Object.saveUrlPreviewSettings (http://localhost:8080/bundles/_dev_/bundle.js:129413:47)
    at Object._calcSavePromises (http://localhost:8080/bundles/_dev_/bundle.js:129366:23)
    at http://localhost:8080/bundles/_dev_/bundle.js:129296:50
From previous event:
    at Object.save (http://localhost:8080/bundles/_dev_/bundle.js:129295:41)
    at Object.onSettingsSaveClick (http://localhost:8080/bundles/_dev_/bundle.js:79028:33)
    at

saveSettings was indeed removed, which I guess is intentional as SettingsFlag seems to save itself by default on change? Not sure though, @turt2live ?

[turt2live]

looks right. Merging in the event we need to revert #2559 and want working settings.

This view otherwise won't survive very long though.