fence_kdump times out when fence_kdump_nodes is not specified with kexec-tools version 2.0.15 or later

Issue

• I need to capture a vmcore from a cluster node, but fence_kdump times out every time that node crashes.
• fence_kdumpfails with "timeout after 60 seconds" and the node gets fenced before the core is dumped.
• If I test fence_kdump by panicking a node, fence_kdump fails with a time out error. If I take the node out of the cluster and panic it, it dumps a core successfully.