Created attachment 908455 [details]
firebug raises NetworkError 400 bad request

Description of problem:
I was trying to install package on bulk systems and forgot to select the systems. when I clicked on "install" button, UI raised a notification:

"No systems have been specified." 

But got a long exception with 400 Bad request in production.log:

Processing by Katello::Api::V2::SystemsBulkActionsController#install_content as JSON
  Parameters: {"included"=>{"ids"=>[], "resources"=>[], "search"=>nil}, "excluded"=>{"ids"=>[]}, "content_type"=>"package", "content"=>["zsh"], "organization_id"=>"1", "api_version"=>"v2", "systems_bulk_action"=>{"included"=>{"ids"=>[], "resources"=>[], "search"=>nil}, "excluded"=>{"ids"=>[]}, "content_type"=>"package", "content"=>["zsh"], "organization_id"=>"1"}}
Katello::HttpErrors::BadRequest: No systems have been specified.
/opt/rh/ruby193/root/usr/share/gems/gems/katello-1.5.0/app/controllers/katello/api/v2/systems_bulk_actions_controller.rb:204:in `find_systems'
/opt/rh/ruby193/root/usr/share/gems/gems/katello-1.5.0/app/controllers/katello/api/v2/systems_bulk_actions_controller.rb:179:in `find_editable_systems'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:553:in `block (3 levels) in _run__1808844839954401441__process_action__3644850479203537843__callbacks'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:215:in `block in _conditional_callback_around_9991'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:326:in `around'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:310:in `_callback_around_2816'


Also, firebug raises NetworkError 400 Bad request

Version-Release number of selected component (if applicable):
sat6 beta snap9 compose2

How reproducible:
always

Steps to Reproduce:
1. install package via Bulk Actions but without selecting any content-host
2.
3.

Actual results:
firebug raises NetworkError 400 Bad request
production.log also throws exception with 400 Bad request

Expected results:
user should just get this error:
"No systems have been specified." 

firebug should not raise any error and no exception should be there in production.log

Additional info: