go2tv: re-enable SSDP search patch

overlays/preferences.nix

@@ -67,6 +67,23 @@ in
   #   withSamba = false;
   # };
 
+  go2tv = super.go2tv.overrideAttrs (upstream: {
+    # XXX(2025-02-12): with release 1.18.0 (due to a4cd63f512), listing devices gives error (even with UDP 1900 whitelisted in firewall):
+    # > Encountered error(s): checkflags error: checkTflag service loading error: loadSSDPservices: No available Media Renderers
+    # this would apparently be because many UPnP servers do not respond to requests _from_ port 1900.
+    # still present in 1.18.1.
+    #
+    # a commit to gssdp (177f2772cf) suggests this is due to "security reasons" (perhaps it allows neighbors to hole-punch port 1900 of clients?)
+    # although it itself responds perfectly fine to M-SEARCH requests from port 1900.
+    # "DLNA requirement 7.2.3.4" could shed some light, but it's a private spec.
+    # so just don't use port 1900 for now.
+    #
+    # done as overlay instead of in hosts/common/programs/go2tv.nix so that python consumers like sane-cast also get this fix.
+    postPatch = (upstream.postPatch or "") + ''
+      substituteInPlace devices/devices.go --replace-fail "port := 1900" "port := 1901"
+    '';
+  });
+
   # gnome-control-center = super.gnome-control-center.override {
   #   # i build goa without the "backend", to avoid webkit_4_1.
   #   # however gnome-control-center *directly* uses goa-backend because it manages the accounts...