Bump version in master

This prepares for a new Gpg4win release and distinguishes
the version between 20.12 branch.

CMakeLists.txt

-set(kleopatra_version 3.1.12)
+set(kleopatra_version 3.1.14)
 # The following is for Windows. Keep in line with kleopatra_version.
-set(kleopatra_fileversion 3,1,12,0)
+set(kleopatra_fileversion 3,1,14,0)
 cmake_minimum_required(VERSION 3.5)
 project(kleopatra VERSION ${kleopatra_version})