Update setup.py and fix minor issues.

gns3server/compute/dynamips/nodes/ethernet_switch.py

@@ -87,6 +87,7 @@ class EthernetSwitch(Device):
         self._mappings = {}
         self._telnet_console = None
         self._telnet_shell = None
+        self._telnet_server = None
         self._console = self._manager.port_manager.get_free_tcp_port(self._project)
         if ports is None:
             # create 8 ports by default
@@ -217,8 +218,9 @@ class EthernetSwitch(Device):
         Deletes this Ethernet switch.
         """
         yield from self._telnet.close()
-        self._telnet_server.close()
-        
+        if self._telnet_server:
+            self._telnet_server.close()
+
         for nio in self._nios.values():
             if nio:
                 yield from nio.close()