do not write ,,garbage'' to known_hosts file(s)

paramiko/client.py

@@ -193,7 +193,6 @@
             self.load_host_keys(self.known_hosts)
 
         f = open(filename, 'w')
-        f.write('# SSH host keys collected by paramiko\n')
         for hostname, keys in self._host_keys.iteritems():
             for keytype, key in keys.iteritems():
                 f.write('%s %s %s\n' % (hostname, keytype, key.get_base64()))