(bug 51684) Modify two variables for Ukrainian Wikisource

Adding namespaces 102 and 252 to $wgNamespacesToBeSearchedDefault
and namespaces 102, 250 and 252 to $wgContentNamespaces per bug
request and community consensus.

Bug: 51684
Change-Id: I326a56e4e7a67ab156c3bc3fbc21d7b0a2695133