Fixed form field name for deployment dsl

Without this saving the crowbar proposal after the initial deployment fails
with an "can't convert nil into String" error.

Fixes https://bugzilla.novell.com/show_bug.cgi?id=883408
(cherry picked from commit 9162532520d7e1972ad4d6e8052e539571237450)
Merge pull request #1069 from rhafer/fix_deployment_save

Fixed form field name for deployment dsl