Fixes checks for free console and aux ports.

gns3server/modules/iou/iou_device.py

@@ -793,7 +793,7 @@ class IOUDevice(object):
             socket_type = socket.SOCK_STREAM
 
         for port in range(start_port, end_port):
-            if port > end_port:
+            if port + 1 == end_port:
                 raise IOUError("Could not find a free port between {0} and {1}".format(start_port, end_port))
             try:
                 if ":" in host: