Update spacewalk-orgclone-channel.py

['checksum_label'] Could be set to 'none' which means the key/val pair isn't set, which causes the script to fail. This change ensures checksum occurs on the new channel
Merge pull request #4 from dodwmd/patch-1

Update spacewalk-orgclone-channel.py: Fixed missing checksum entry in create_dst_channel (Thanks to dodwmd)