Log Message:
Update libproxy to 0.4.13

Upstream changes:

 - Allow linking webkit pacrunner against javascriptcore-4.0 (webkit2).
 - Allow to disable building of the KDE module (-DWITH_KDE=ON/OFF).
 - Fix compilation errors with CLang on MacOSX.
 - bindings: perl: Add an option to explicitly link against libperl.so Some
   distributions want to do it, other prefer not to, the library is anyway in
   context of perl.
 - config_kde: Add a basic cache and invalidation: performance improvement for
   the KDE module.

Upgrade during freeze to fix upstream regression with Qt4 and Qt5 clashes.

Requested by Ralf Nolden <nolden@kde.org>

Approved by <pkgsrc-pmc>.