fpwizard: Switch page after checking parameters

The parameter check was triggered by a grid clear event which was sent
after the current page number was changed, creating a mismatch between
the old and new parameter list lengths.

Fixes: lp:1754738
* https://bugs.launchpad.net/kicad/+bug/1754738

pcbnew/footprint_wizard_frame.cpp

@@ -348,8 +348,8 @@ void FOOTPRINT_WIZARD_FRAME::ReCreateParameterList()
     if( footprintWizard == NULL )
         return;
 
-    m_parameterGridPage = m_pageList->GetSelection();
     m_parameterGrid->ClearGrid();
+    m_parameterGridPage = m_pageList->GetSelection();
 
     if( m_parameterGridPage < 0 )   // Should not happen
         return;