Footprint Editor: fix a crash when the dialog to set pad properties is called...

Footprint Editor: fix a crash when the dialog to set pad properties is called from the main toolbar (i.e. to define the default setting for new pads, and not to edit an existing pad)

pcbnew/dialogs/dialog_pad_properties.cpp

@@ -149,10 +149,10 @@ DIALOG_PAD_PROPERTIES::DIALOG_PAD_PROPERTIES( PCB_BASE_FRAME* aParent, D_PAD* aP
 {
     m_canUpdate  = false;
     m_parent     = aParent;
-    m_currentPad = aPad;
+    m_currentPad = aPad;        // aPad can be NULL, if the dialog is calleg
+                                // from the modoule editor to set default pad characteristics
     m_board      = m_parent->GetBoard();
-    m_dummyPad   = new D_PAD( aPad->GetParent() );
-    m_padMaster.SetParent( aPad->GetParent() );
+    m_dummyPad   = new D_PAD( (MODULE*) NULL );
 
     if( aPad )
         m_dummyPad->Copy( aPad );