[bp/r46571][FIX] Hack to fix samerow problem. May apply to other types too.
The field default value was not used when the option value is empty, which occurs when only "Add Field" is selected.
Caused samerow='No' to be displayed in the dialog, when no value is set. But samerow has default value = Yes.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/10.x@46572 b456876b-0849-0410-b77d-98878d47e9d5