AgentX socket problem

As soon an AgentX master agent is started twice
with the same cofniguration, the master agent
does not handle new subagents.
Already connected subagents keep working.

This can be done as follows.
1) Start a master agent.
2) Connect a subagent.
3) Start a master agent with the same agentx
socket (Unix Domain Socket)
4) The new master agent will not start up due to
the SNMP UDP port is already occupied.
5) New subagent connection fail with cannot
connect.