Correct Dutch language name to "Nederlands".

"Nederlandse" is the adjective form which is not appropriate here;
only used stand-alone when referring to nationality.

common/pgm_base.cpp

@@ -102,7 +102,7 @@ LANGUAGE_DESCR LanguagesList[] =
     { wxLANGUAGE_ITALIAN,    ID_LANGUAGE_ITALIAN,    wxT( "Italiano" ), true },
     { wxLANGUAGE_LITHUANIAN, ID_LANGUAGE_LITHUANIAN, wxT( "Lietuvių" ), true },
 //    { wxLANGUAGE_HUNGARIAN,  ID_LANGUAGE_HUNGARIAN,  wxT( "Magyar" ),   true },
-    { wxLANGUAGE_DUTCH,      ID_LANGUAGE_DUTCH,      wxT( "Nederlandse" ), true },
+    { wxLANGUAGE_DUTCH,      ID_LANGUAGE_DUTCH,      wxT( "Nederlands" ), true },
     { wxLANGUAGE_JAPANESE,   ID_LANGUAGE_JAPANESE,   wxT( "日本語" ),    true },
     { wxLANGUAGE_THAI,       ID_LANGUAGE_THAI,       wxT( "ภาษาไทย" ),    true },
     { wxLANGUAGE_POLISH,     ID_LANGUAGE_POLISH,     wxT( "Polski" ),   true },