Bug 29315: Remove warnings from Search.t

Bug 29315: Remove warnings from Search.t

The syspref SearchLimitLibrary was requested but I don't know what to
say; this indicates that the test requires updating at
t/db_dependent/Search.t line 198.
The syspref FacetOrder was requested but I don't know what to say; this
indicates that the test requires updating at t/db_dependent/Search.t
line 198.
The syspref OPACResultsUnavailableGroupingBy was requested but I don't
know what to say; this indicates that the test requires updating at
t/db_dependent/Search.t line 198.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>