[tools] testbot/cgi: Fix getting the property descriptors in FormPage::SaveProperties().

[Francois Gouget]

The base form page has no Collection field.

Signed-off-by: Francois Gouget 
---
This worked because the only classes that call SaveProperties() are 
those that derive from ItemPage which does set the Collection field. 
Also FormPage::PropertyDescriptors is initialized from the collection 
property descriptors by ItemPage::_initialize().
---
 testbot/lib/ObjectModel/CGI/FormPage.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/testbot/lib/ObjectModel/CGI/FormPage.pm b/testbot/lib/ObjectModel/CGI/FormPage.pm
index 43b9b59ce5..1910bf743b 100644
--- a/testbot/lib/ObjectModel/CGI/FormPage.pm
+++ b/testbot/lib/ObjectModel/CGI/FormPage.pm
@@ -368,7 +368,7 @@ sub SaveProperties($)
     }
   }

-  foreach my $PropertyDescriptor (@{$self->{Collection}->GetPropertyDescriptors})
+  foreach my $PropertyDescriptor (@{$self->GetPropertyDescriptors()})
   {
     if ($PropertyDescriptor->GetClass() eq "Basic" &&
         $PropertyDescriptor->GetType() eq "B" &&