Bug fix when channel has no stdout output

Author: pkittenis

pssh.py

@@ -117,11 +117,10 @@ def exec_command(self, command, sudo=False, **kwargs):
         logger.debug("Running command %s on %s", command, self.host)
         channel.exec_command(command, **kwargs)
         logger.debug("Command finished executing")
-        while not channel.recv_ready():
+        while not (channel.recv_ready() or channel.closed):
             gevent.sleep(.2)
         return channel, self.host, stdout, stderr
 
-
 class ParallelSSHClient(object):
     """Uses SSHClient, runs command on multiple hosts in parallel"""