v.external.out: do not define default format

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@44806 15284696-431f-4ddb-bdfa-cd5b030d7da7

vector/v.external.out/args.c

@@ -20,8 +20,7 @@ void parse_args(int argc, char **argv,
     options->format->required = YES;
     options->format->type = TYPE_STRING;
     options->format->options = format_list();
-    options->format->answer = "ESRI Shapefile";
-
+ 
     options->opts = G_define_option();
     options->opts->key = "options";
     options->opts->description = _("Creation options");