Fix GenericPush.run references to self for push_trans_only
Fix GenericPush.run references to self for push_trans_only

This allows pushing specific translations to work. eg:

zanata push --push-type target --lang af

zanata/zanata-python-client,sundeep-co-in/zanata-python-client,sundeep-co-in/zanata-python-client,zanata/zanata-python-client