dont log error when remote client drops connection on Windows (fix #427)

ChangeLog

@@ -6,6 +6,9 @@ vNEXT:
 
 	Introduce autoconf to adapt to landlock presence.
 
+	Close connexion without error message if remote
+	client forcefully closes connexion, for Windows.
+
 v2.0.1:	
 	Fix resolve_on_forward setting, which would crash
 	sslh reliably.

common.c

@@ -482,6 +482,7 @@ int fd2fd(struct queue *target_q, struct queue *from_q)
            return FD_NODATA;
 
        case ECONNRESET:
+       case ENOTSOCK:
        case EPIPE:
            return FD_CNXCLOSED;
        }