Remove the apparently unneeded wxPGPropArgCls default ctor.

This ctor didn't initialize the flags correctly and could result in a crash
when a default constructed object was destroyed.

Closes #15174.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73898 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/propgrid/propgridiface.h

@@ -29,7 +29,6 @@
 class WXDLLIMPEXP_PROPGRID wxPGPropArgCls
 {
 public:
-    wxPGPropArgCls() { }
     wxPGPropArgCls( const wxPGProperty* property )
     {
         m_ptr.property = (wxPGProperty*) property;