jquery.tablesorter.test: Reset transform tables in mw.config

Having $wgLanguageCode set to "de" will pre-populate the transform tables
in mw.config for German, but the English transform tables are expected
(which are empty) for the jquery.tablesorter tests to pass.

Change-Id: Ief16ff9d0767c6c9332bc4e56c96be3d7d4f6ac8
Merge "jquery.tablesorter.test: Reset transform tables in mw.config"