Bug 8686: Raise required version of URI::Escape to 3.31

Bug 8686: Raise required version of URI::Escape to 3.31

Raises the minimum required version of URI::Escape from
1.36 to 3.31.

TEST PLAN
---------
1) git branch -b bug_8686 origin/master
2) ./koha_perl_deps.pl -a | grep URI
   -- it will list 1.36 required
3) git bz apply 8686
4) ./koha_perl_deps.pl -a | grep URI
   -- it will list 3.31 required
5) koha qa test tools

NOTE: Also default in Ubuntu 14.04 LTS,
      not just Wheezy as noted in comment #15.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@koha-community.org>
Signoff based on Nicole's comment (bug 9990 comment 6):
"This stops happening if you upgrade URI::Escape to
3.31.  We should make it clear in the Perl Modules page that an upgrade
is needed."
Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>