minor pylint fixes for minion.py

salt/minion.py

@@ -23,7 +23,7 @@ import zmq
 # Import salt libs
 from salt.exceptions import AuthenticationError, \
     CommandExecutionError, CommandNotFoundError, SaltInvocationError, \
-    SaltClientError, SaltReqTimeoutError
+    SaltReqTimeoutError
 import salt.client
 import salt.crypt
 import salt.loader
@@ -639,7 +639,6 @@ class Minion(object):
                 if socket in socks and socks[socket] == zmq.POLLIN:
                     payload = self.serial.loads(socket.recv())
                     self._handle_payload(payload)
-                    last = time.time()
                 time.sleep(0.05)
                 multiprocessing.active_children()
                 self.passive_refresh()