Form/AdSpace should should be a single select form element, not a multiple.

This fixes bug #10835.

docs/changelog/7.x.x.txt

@@ -1,4 +1,5 @@
 7.7.19
+ - fixed #10835: Ad Sales: Ad Space field not user-friendly
  - fixed #10841: Ad Sales: hover help spelling error
  - fixed #10833: Calendar feeds not versioned, not duplicated
  - fixed #10831: Graphing tab in Poll is not i18n'ed

lib/WebGUI/Asset/Sku/Ad.pm

@@ -78,7 +78,6 @@ sub definition {
         adSpace => {
             tab             => "properties",
             fieldType       => "AdSpace",
-            namespace       => "AdSku",
             label           => $i18n->get("property ad space"),
             hoverHelp       => $i18n->get("property ad Space help"),
         },

lib/WebGUI/Form/AdSpace.pm

@@ -15,9 +15,8 @@ package WebGUI::Form::AdSpace;
 =cut
 
 use strict;
-use base 'WebGUI::Form::SelectList';
+use base 'WebGUI::Form::SelectBox';
 use WebGUI::International;
-use WebGUI::SQL;
 
 =head1 NAME