Simplified SocketInitiator.initialize()

Sessions are already registered in `createSessionInitiators()` via `SessionFactory`

Author: chrjohn

quickfixj-core/src/main/java/quickfix/SocketInitiator.java

@@ -125,9 +125,6 @@ private void initialize() throws ConfigError {
             if (isStarted.compareAndSet(false, true)) {
                 eventHandlingStrategy.setExecutor(longLivedExecutor);
                 createSessionInitiators();
-                for (Session session : getSessionMap().values()) {
-                    Session.registerSession(session);
-                }
                 startInitiators();
                 eventHandlingStrategy.blockInThread();
             }