Bug 16869: Silence and catch warnings in t/db_dependent/SuggestionEngine_ExplodedTerms.t

Bug 16869: Silence and catch warnings in t/db_dependent/SuggestionEngine_ExplodedTerms.t

By properly defining a opachtdocs (intranethtdocs was done too)
in the mock function, uninitialized variable warnings are
eliminated. Given that we can check if $KOHA_CONF is defined or
not, we can catch the warning as part of testing, so the output
of the test is cleaner.

TEST PLAN
---------
1) unset KOHA_CONF
2) prove t/db_dependent/SuggestionEngine_ExplodedTerms.t
   -- lots of noise
3) apply patch
4) prove t/db_dependent/SuggestionEngine_ExplodedTerms.t
   -- no noise
5) prove -v t/db_dependent/SuggestionEngine_ExplodedTerms.t
   -- see the warnings were caught and not just ignored.
6) run koha qa test tools

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
No warnings. Works as advertised

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit 5ec641fbbb67501e2a71be64b12c9224caee1b55)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>