Fix default button option on close

The default is meant to be "Save" but "Discard" was selected due to ID
ordering on creation.  Setting the focus before setting the default
makes the "Save" option the highlighted option that can be selected
immediately by pressing enter.

(cherry picked from commit a0f477cc5f)

common/confirm.cpp

@@ -166,6 +166,7 @@ public:
 
         m_sdbSizerOK->SetLabel( aOKLabel );
         m_sdbSizerCancel->SetLabel( aCancelLabel );
+        m_sdbSizerOK->SetFocus();
         m_sdbSizerOK->SetDefault();
 
         FinishDialogSettings();