Delete SocketSession which was only referenced and not used in unit-tests.

Ludovic Poitou

06.42.2013 d8172652687bb03d86c5d0d8050f1370dde0af56

opends/src/server/org/opends/server/replication/protocol/SocketSession.java does not exist in tree 42c5d1b1b75b97953c87230164ad5e1df0988176