[Pacemaker] Minor buffer overflow..

[Rob Thomas]

I was idly wondering why the SMTP and SNMP modules were disabled by
default on the RHEL builds, and was in the middle of writing a shell
script to duplicate them when I noticed there was a tiny buffer
overflow in crm_mon.

This may be why it's disabled by default?

Patch:

https://github.com/xrobau/pacemaker/commit/b1515e3f83fceeac951de8823d718bdf13e4a093

--Rob