fixed an issue cuaisng router to die

- router should not die when an error happens when connecting to HW
+ install will restart changed network interfaces

router.py

@@ -1,3 +1,4 @@
+import sys
 import socket
 from select import select
 from serial import serial_for_url
@@ -98,7 +99,7 @@ class AcceptHandler:
     
     :param: port offered port for routing
     :param: addr where to route
-    :param: iocls the io ahndler class, currently TcpHandler or SerialHandler
+    :param: iocls the io handler class, currently TcpHandler or SerialHandler
     :param: maxcount the maximal number of concurrent connections. defauls to 1
             as a side effect, if the destination is a web server, the traffic
             are serialized (only one connection at a time), which helps for
@@ -140,8 +141,13 @@ class AcceptHandler:
         if not self.available:
             self.pending += 1
             return
-        client, addr = self.socket.accept()
-        handler = self.iocls(client, self)
+        try:
+            client, addr = self.socket.accept()
+            handler = self.iocls(client, self)
+        except Exception as e:
+            print('ERROR creating %s(%r)' % (self.iocls.__name__, self.addr))
+            client.close()
+            return
         self.readers[client.fileno()] = handler.request
         self.readers[handler.fno] = handler.reply
         self.available -= 1