don't check deb distro when distro is confirmed to be CentOS/RHEL (#693)
don't check deb distro when distro is confirmed to be CentOS/RHEL (#693)

* don't check deb distro when distro is confirmed to be CentOS/RHEL

Fixes #691

Signed-off-by: Amos Kong <eb01d8f828a6c9a20be4534e72e049aaf41503df@scylladb.com>

* sdcm/cluster: refactor distro probe function

Currently _get_distro() casually update self.distro attribute, this patch added
getter, setter, and a function to probe distro type.

Reference: https://en.wikipedia.org/wiki/Mutator_method

Signed-off-by: Amos Kong <eb01d8f828a6c9a20be4534e72e049aaf41503df@scylladb.com>

scylladb/scylla-cluster-tests,amoskong/scylla-cluster-tests,scylladb/scylla-longevity-tests,amoskong/scylla-cluster-tests,scylladb/scylla-longevity-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,amoskong/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-longevity-tests,amoskong/scylla-cluster-tests,amoskong/scylla-cluster-tests,scylladb/scylla-cluster-tests