Updated mediawiki/extensions
Project: mediawiki/extensions/BookManagerv2  a1e45aff11a8411b3b8d3d0b2cf81f4a05693a8b

Change back to using dot concatenation.

mwalker has informed me that dot concatenation is more efficient
than creating an array and imploding it, so I'm switching back.

Change-Id: Ibf2aeb6fed373cc5dc2b3fde5737078a4b3a336d