remove a static wxString constructor which was out of sequence with another...

remove a static wxString constructor which was out of sequence with another dependent one, at least with one toolchain.

pcbnew/class_netclass.cpp

@@ -36,7 +36,7 @@
 
 
 // This will get mapped to "kicad_default" in the specctra_export.
-const wxString NETCLASS::Default = wxT("Default");
+const wxChar NETCLASS::Default[] = wxT( "Default" );
 
 // Initial values for netclass initialization
 int NETCLASS::DEFAULT_CLEARANCE  = DMils2iu( 100 );  // track to track and track to pads clearance

pcbnew/class_netclass.h

@@ -80,7 +80,7 @@ protected:
 
 public:
 
-    static const wxString Default;      ///< the name of the default NETCLASS
+    static const wxChar Default[];      ///< the name of the default NETCLASS
 
     /**
      * Constructor