nextcloud*: enable structuredAttrs, strictDeps

Fixes:
```
- Attribute `pkgs.nextcloud34` is a new package with `strictDeps` unset or set to `false`.
  Please enable `strictDeps = true;` in pkgs/top-level/all-packages.nix.
 (https://github.com/NixOS/nixpkgs-vet/wiki/NPV-164)
- Attribute `pkgs.nextcloud34` is a new package with `__structuredAttrs` unset or set to `false`.
  Please enable `__structuredAttrs = true;` in pkgs/top-level/all-packages.nix.
 (https://github.com/NixOS/nixpkgs-vet/wiki/NPV-166)
```

pkgs/servers/nextcloud/default.nix

@@ -20,18 +20,14 @@ let
       pname = "nextcloud";
       inherit version;
 
+      __structuredAttrs = true;
+      strictDeps = true;
+
       src = fetchurl {
         url = "https://download.nextcloud.com/server/releases/nextcloud-${version}.tar.bz2";
         inherit hash;
       };
 
-      passthru = {
-        tests = lib.filterAttrs (
-          key: _: (lib.hasSuffix (lib.versions.major version) key)
-        ) nixosTests.nextcloud;
-        inherit packages;
-      };
-
       installPhase = ''
         runHook preInstall
         mkdir -p $out/
@@ -39,6 +35,13 @@ let
         runHook postInstall
       '';
 
+      passthru = {
+        tests = lib.filterAttrs (
+          key: _: (lib.hasSuffix (lib.versions.major version) key)
+        ) nixosTests.nextcloud;
+        inherit packages;
+      };
+
       meta = {
         changelog = "https://nextcloud.com/changelog/#${lib.replaceStrings [ "." ] [ "-" ] version}";
         description = "Sharing solution for files, calendars, contacts and more";