dist: use /usr/bin/python3.4 for idl-compiler.py on CentOS
dist: use /usr/bin/python3.4 for idl-compiler.py on CentOS

Fixes #923

Signed-off-by: Takuya ASADA <4ebfb6f510af412d6e89fefa3ab96d9c8b5e3fff@scylladb.com>
Message-Id: <1455826201-11333-1-git-send-email-4ebfb6f510af412d6e89fefa3ab96d9c8b5e3fff@scylladb.com>

avikivity/scylla,kjniemi/scylla,scylladb/scylla,scylladb/scylla,kjniemi/scylla,duarten/scylla,scylladb/scylla,scylladb/scylla,duarten/scylla,raphaelsc/scylla,avikivity/scylla,avikivity/scylla,duarten/scylla,raphaelsc/scylla,raphaelsc/scylla,kjniemi/scylla