Description of problem:
create app without an existing domain will get the following error info:
/usr/lib/ruby/gems/1.8/gems/rhc-0.89.10/lib/rhc-common.rb:384:in `create_app': undefined method `[]' for nil:NilClass (NoMethodError)
	from /usr/lib/ruby/gems/1.8/gems/rhc-0.89.10/bin/rhc-app:231:in `create_app'
	from /usr/lib/ruby/gems/1.8/gems/rhc-0.89.10/bin/rhc-app:565
	from /usr/bin/rhc-app:19:in `load'
	from /usr/bin/rhc-app:19


Version-Release number of selected component (if applicable):
rhc-0.89.10

How reproducible:
always

Steps to Reproduce:
1.register an new user 
2.try to create app without create domain
3.
  
Actual results:
unexpected error message appears

Expected results:
should have meaningful warning message tell user that domain is required.

Additional info: