Bug 14425: Typo in C4::Context IsSuperLibrarian perldoc

Bug 14425: Typo in C4::Context IsSuperLibrarian perldoc

TEST PLAN
---------
1) git checkout -b bug_14425 origin/master
2) perldoc C4::Context
   /IsSuperlibr
   -- see it is bad.
3) apply patch
4) perldoc C4::Context
   /IsSuperLibr
   -- see it is fixed.
5) koha qa test tools.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Fix typo, no errors.

Signed-off-by: Jonathan Druart <jonathan.druart@koha-community.org>
% git grep -i IsSuperLibrarian|wc -l
55
% git grep IsSuperLibrarian|wc -l
55
Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>