core: osinfo properties - added 3.4 values

Since 3.4 cluster version has been recently introduced,
appropriate values should be manually added explicitly.

Note: this is a temporary solution until the implementation
      of cluster versions inheritance in OsInfo infrastructure.

Change-Id: Ib4b2d3b3eb14d368814392cfcb63e6c8648d05cc
Signed-off-by: Daniel Erez <derez@redhat.com>