Bug 16449: Remove "no method selected" warning from unimarc_field_4XX

Bug 16449: Remove "no method selected" warning from unimarc_field_4XX

Because of bug 14828, the unimarc_field_4XX now raises a warning:
"No method selected!"

There are no need to select an item type on this page, the default (all)
is always selected.

Test plan:
Link the unimarc_field_4XX value builder with on of the subfield
Edit a record, click on the value builder icon
Note the warning without the patch and that it's gone with the patch
applied

NOTE: Code fix that I derived was identical. Ran
 prove t/db_dependent/FrameworkPlugin.t
to confirm it works.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>