Updated mediawiki/extensions
Project: mediawiki/extensions/VectorBeta  873603ea8131fc24054b9f7c154c34b20405a965

Path typo in resources

fixedheader should be fixedHeader. This left module
'skins.vector.headerjs.beta' in an error state.

Change-Id: Iea60dc2d9351eaec8b8bb20a0e132980449d2b41