vmd: allow agentx to reconnect closed components

[Martijn van Duren]

This builds on top of the previous two diffs.

Easiest way to test is to add the following line to vm.conf in
combination with snmpd(8):
agentx context foo

This results in:
[fd:6 sess:4009008336 ctx:foo]: region .1.3.6.1.2.1.236: opening
[fd:6 sess:4009008336 ctx:foo]: region .1.3.6.1.2.1.236: Unsupported context

If you then remove the "context foo" part and run vmctl reload vmd
should properly register:
[fd:6 sess:4009008336 ctx:<default>]: region .1.3.6.1.2.1.236: opening
[fd:6 sess:4009008336 ctx:<default>]: region .1.3.6.1.2.1.236: open

OK?

martijn@

Index: vm_agentx.c
===================================================================
RCS file: /cvs/src/usr.sbin/vmd/vm_agentx.c,v
retrieving revision 1.1
diff -u -p -r1.1 vm_agentx.c
--- vm_agentx.c 13 Sep 2022 10:28:19 -0000      1.1
+++ vm_agentx.c 11 Oct 2022 18:52:45 -0000
@@ -321,6 +321,7 @@ vm_agentx_configure(struct vmd_agentx *e
                changed = 1;
        }
 
+       agentx_retry(conn->agentx);
        if (!changed)
                return;