nixos/searx: move network.target from wantedBy to after

In 623664e84f this part was refactored,
however network.target does not make sense in wantedBy and must be part of after.

(cherry picked from commit bcc1b762e9)

nixos/modules/services/networking/searx.nix

@@ -252,12 +252,12 @@ in
 
     systemd.services.searx = mkIf (!cfg.runInUwsgi) {
       description = "Searx server, the meta search engine.";
-      wantedBy = [
-        "network.target"
-        "multi-user.target"
-      ];
+      wantedBy = [ "multi-user.target" ];
       requires = [ "searx-init.service" ];
-      after = [ "searx-init.service" ];
+      after = [
+        "searx-init.service"
+        "network.target"
+      ];
       serviceConfig =
         {
           User = "searx";