Description of problem:
Cloning channel via API  generates ISE if no "summary" is provided.
The problem is that there is no check as for label, name, gpg.

Version-Release number of selected component (if applicable):
spacewalk-java-2.1.28-1

How reproducible:
100%

Steps to Reproduce:
1. Execute the following script:

import sys, xmlrpclib
RHN_SERVER='https://xxxx.redhat.com/rpc/api'
RHN_USER='xxxx'
RHN_PASS='xxxx'
client = xmlrpclib.Server(RHN_SERVER, verbose=0)
key = client.auth.login(RHN_USER, RHN_PASS)

client.channel.software.create(key,'test_label','test_name','summary','channel-x86_64','')
client.channel.software.clone(key,'test_label',{'name':'clone-test_name','label':'clone-test_label',},True)

Actual results:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib64/python2.7/xmlrpclib.py", line 1224, in __call__
    return self.__send(self.__name, args)
  File "/usr/lib64/python2.7/xmlrpclib.py", line 1578, in __request
    verbose=self.__verbose
  File "/usr/lib64/python2.7/xmlrpclib.py", line 1264, in request
    return self.single_request(host, handler, request_body, verbose)
  File "/usr/lib64/python2.7/xmlrpclib.py", line 1312, in single_request
    response.msg,
xmlrpclib.ProtocolError: <ProtocolError for ibm-x3650m4-03-vm08.lab.eng.brq.redhat.com/rpc/api: 500 Internal Server Error>

Expected results:
No ISE, some explanation message.

Additional info: