Revert "Messanger v2 should be enabled in Nautilus"

This reverts commit 64c8854382.

Change-Id: Ifc066c9548b7915beb14cd132bf8a248b18d4ac1

ceph/utils.py

@@ -2147,13 +2147,6 @@ def roll_monitor_cluster(new_version, upgrade_key):
             wait_for_all_monitors_to_upgrade(new_version=new_version,
                                              upgrade_key=upgrade_key)
             bootstrap_manager()
-        # NOTE(icey)
-        # In Ceph Nautilus, the msgr2 messaging protocol is preferres
-        # so we enable it here after an upgrade. Any Ceph version after
-        # Nautilus should pick it up automatically as it should be set
-        # at bootstrap.
-        if new_version == 'nautilus':
-            setup_msgr2()
     except ValueError:
         log("Failed to find {} in list {}.".format(
             my_name, mon_sorted_list))
@@ -2937,16 +2930,6 @@ def bootstrap_manager():
         service_restart(unit)
 
 
-def setup_msgr2():
-    """
-    Update Ceph to use msr2.
-
-    :raises: subprocess.CalledProcessError if the command fails
-    """
-    cmd = ['ceph', 'mon', 'enable-msgr2']
-    subprocess.check_call(cmd)
-
-
 def osd_noout(enable):
     """Sets or unsets 'noout'