(bug 56384) Configure $wgImportSources for dewikisource

Adding dewiki, dewikibooks, dewikiquote, dewikiversity,
dewiktionary, enwikisource, frwikisource and lawikisource
in addition to the family default commonswiki and metawiki
as well as the already existing oldwikisource.

See bug for URL with on-wiki consensus for the addition
of these new import sources.

Bug: 56384
Change-Id: I8ad4cf7661ec56cab44d26fcc6b3add6b7d82431
Merge "(bug 56384) Configure $wgImportSources for dewikisource"