Duplicate entry of "output" keyword (#1001)

Duplicate entry of "output" keyword

vector/v.out.ogr/main.c

@@ -84,7 +84,6 @@ int main(int argc, char *argv[])
     G_add_keyword(_("export"));
     G_add_keyword(_("output"));
     G_add_keyword("OGR");
-    G_add_keyword(_("output"));
 
     module->label =
 	_("Exports a vector map layer to any of the supported OGR vector formats.");