Updated mediawiki/extensions
Project: mediawiki/extensions/SecurePoll  176992c8d129aa8ddc1d715b4099e7ea909bf864

Fix SecurePollContent handling

It was accidentally creating an instance of the parent class,
JsonContent, instead.

Change-Id: I5a0f7eaad1143b39c9045337d88cdfeb1bcb8f82