messages: Initializing uninitialized members MMonProbe

messages: Initializing uninitialized members MMonProbe

Fixes coverity Issue:

** 717299 Uninitialized scalar field
2. uninit_member: Non-static class member op is not initialized in this constructor nor in any functions that it calls.
  	4. uninit_member: Non-static class member paxos_first_version is not initialized in this constructor nor in any functions that it calls.
   	6. uninit_member: Non-static class member paxos_last_version is not initialized in this constructor nor in any functions that it calls.
   	8. uninit_member: Non-static class member has_ever_joined is not initialized in this constructor nor in any functions that it calls.

CID 717299 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
10. uninit_member: Non-static class member required_features is not initialized in this constructor nor in any functions that it calls

Signed-off-by: Amit Kumar amitkuma@redhat.com