Improve Linux/macOS compatibility on socket connect w/ empty hostname

Author: pjkundert

server/enip/client.py

@@ -422,7 +422,8 @@ def __init__( self, host, port=None, timeout=None, dialect=None, profiler=None,
                 port	= port_cnf # only override if nonexistent/None
         if port is None:
             port		= defaults.address[1]
-        self.addr		= str( host ),int( port ) # host may be ip_address; str-ingify...
+        # host may be ip_address; str-ingify, and Linux is strict vs. macOS; default to 'localhost'
+        self.addr		= str( host ) or 'localhost',int( port )
         self.addr_connected	= not ( udp and broadcast )
         self.conn		= None
         self.udp		= udp

server/network.py

@@ -426,7 +426,7 @@ def thread_start( conn, addr ):
                 log.debug( "TCP/IP: Idle Svc after {duration:7.3f}s".format( duration=duration ))
                 idle_service()
         except KeyboardInterrupt as exc:
-            log.warning( "%s server termination: %r", name, exc )
+            log.info( "%s server termination: %r", name, exc )
             control['done']	= True
         except Exception as exc:
             log.warning( "%s server failure: %s\n%s", name,