Description of problem:
inconsistent error message appears when removing non-exsit ssh key between multi ssh key existing and single ssh key existing

Version-Release number of selected component (if applicable):
stage

How reproducible:
always

Steps to Reproduce:
1.create new domain
rhc-create-domain -n testdomain
2.try to remove non-exsiting ssh key
rhc-ctl-domain -r test
3.add a valid ssh key to the domain
rhc-ctl-domain -a key1 -k .ssh/libra_id_rsa2.pub
4.try to remove non-existing ssh key again
rhc-ctl-domain -r test


Actual results:
inconsistent error message shown between step2 and step4

Expected results:
the error message should be unified.

Additional info:
step2:
[bmeng@localhost ~]$ rhc-ctl-domain -r test
Problem reported from server. Response code was 500.
Re-run with -d for more information.

RESULT:
ERROR: Can't remove all ssh keys for user bmeng+5

step4:
[bmeng@localhost ~]$ rhc-ctl-domain -r test
Problem reported from server. Response code was 500.
Re-run with -d for more information.

RESULT:
ERROR: Key name 'test' doesn't exist for user bmeng+5