termination of pipe via delimiter message could stuck when no data were read…

termination of pipe via delimiter message could stuck when no data were read from the pipe (because connection wasn't active) -- fixed

src/session.cpp

@@ -160,6 +160,13 @@ void zmq::session_t::process_plug ()
 
 void zmq::session_t::finalise ()
 {
+    //  There may be delimiter waiting in the inbound pipe, never to be read
+    //  because the connection cannot be established. In order to terminate
+    //  decently in such case, do check_read which will in turn start the pipe
+    //  termination process if there's delimiter in it.
+    if (in_pipe)
+        in_pipe->check_read ();
+
     //  If all conditions are met, proceed with termination:
     //  1. Owner object already asked us to terminate.
     //  2. The pipes were already attached to the session.