r.to.vect: fix type opt description

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@63332 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.to.vect/main.c

@@ -78,6 +78,7 @@ int main(int argc, char *argv[])
     out_opt = G_define_standard_option(G_OPT_V_OUTPUT);
     
     feature_opt = G_define_standard_option(G_OPT_V_TYPE);
+    feature_opt->description = _("Output feature type");
     feature_opt->required = YES;
     feature_opt->multiple = NO;
     feature_opt->options = "point,line,area";