org.epics.pvaccess.client.impl.remote.ChannelImpl can create 2 transports and only release 1 in some situations

[juanfem]

I found two cases when the ChannelImpl can create 2 org.​epics.​pvaccess.​impl.​remote.Transport objects and then release only one when destroying the channel.

1. If 2 network devices are present and EPICS_PVA_AUTO_ADDR_LIST=YES. Then the broadcast during the search receives 2 replies from different IPs, but the server has the same GUID.
2. If the EPICS_PVA_ADDR_LIST include 2 IPs that reach the same server, e.g. 127.0.0.1 and 255.255.255.255. In that case the server has the same GUID as well.

I am creating a Pull request with a proposal for the fix.