[core] add config option to reject pathinfo

(renamed w/ '-' instead of '_' for consistency with other feature flags)

global setting; default enabled to preserve existing behavior

If disabled, 404 Not Found is returned if request processing reaches the
step to check filesystem and path, including pathinfo, does not exist.
  server.feature-flags += ("server.http-pathinfo" => "disabled")

Note: this global feature is separate from static-file.disable-pathinfo,
which only affects requests not handled by any other module, and finally
handled by mod_staticfile.

src/configfile.c

@@ -1330,7 +1330,7 @@ static int config_insert(server *srv) {
     p->defaults.mimetypes = &srv->srvconf.mimetypes_default;/*must not be NULL*/
     p->defaults.h2proto = srv->srvconf.h2proto;
     p->defaults.http_pathinfo =
-      config_feature_bool(srv, "server.http_pathinfo", 1);
+      config_feature_bool(srv, "server.http-pathinfo", 1);
 
     /* initialize p->defaults from global config context */
     if (p->nconfig > 0 && p->cvlist->v.u2[1]) {