syslog-ng: update to version 4.10.0

syslog-ng: update to version 4.10.0

Release notes:
https://github.com/syslog-ng/syslog-ng/releases/tag/syslog-ng-4.10.0

Makefile changes
----------------

1. Disable experimental feature: stackdump
due to issues, which were reported to upstream

2. Disabled example modules to avoid adding libstdc++.so.6 dependency
Fixes:
Package syslog-ng is missing dependencies for the following libraries:
libstdc++.so.6

Other changes
-------------

In syslog-ng 4.8.0, there was added possibility to use value "current"
as version in the config file, so use it, which confirm to use
the latest version instead of bumping the version in the file
manually.

Signed-off-by: Josef Schlehofer <[email protected]>