Updated mediawiki/extensions
Project: mediawiki/extensions/Popups  1877fda6302ba02eb0567deda4d19fe17a1dde6b

Use only px in the stylesheet

Instead of the current incomprehensible mixture of em's and px's.
This will help resolve other positioning bugs with relative ease.

Change-Id: I9d7659736489c461ab8c0f4aa660a3ce2846bd5d