security/keepassx2: Update to 2.0.3

• Update to 2.0.3
• Add LICENSE block
• Register conflicts between keepassx2 and keepassx-devel
• Use CMAKE arguments for ZLIB_SUPPORTS_GZIP instead patch-CMakeLists.txt

PR: 212944
Submitted by: Eric Camachat <eric@camachat.org>
Approved by: koobs (mentor)
MFH: 2016Q4