Conditional closing div on Features/Volumes container

Fixes the bug you can [see here](http://m.code.dev-theguardian.com/cm).
Ultimately only closes of the `js-container--show-more` if it's created.

I will revisit this after releasing the fix as to a nicer way of doing this.

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![Clooooosing](http://www.pop.com.br/imagens/casa/viagem/ferias/1162958_como-deixar-a-casa-segura-enquanto-voce-viaja.gif)