nixos: services: servarr: nzbhydra: fix websockets

From what I could read, NZBHydra2 *might* require proxying websockets in
new versions (better safe than sorry).

modules/nixos/services/servarr/nzbhydra.nix

@@ -17,6 +17,7 @@ in
     my.services.nginx.virtualHosts = {
       nzbhydra = {
         port = 5076;
+        websocketsLocations = [ "/" ];
       };
     };