nextcloudPackages: update

We no longer use fetchzip because nc4nix no longer unpacks the tarball
before computing the hash.

pkgs/build-support/fetchnextcloudapp/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchzip, applyPatches, lib, ... }:
+{ fetchurl, fetchzip, applyPatches, lib, ... }:
 { url
 , hash ? ""
 , sha256 ? ""
@@ -8,19 +8,12 @@
 , patches ? [ ]
 , description ? null
 , homepage ? null
+, unpack ? true # whether to use fetchzip rather than fetchurl
 }:
 applyPatches ({
   inherit patches;
-  src = fetchzip {
+  src = (if unpack then fetchzip else fetchurl) {
     inherit url hash sha256;
-    postFetch = ''
-      pushd $out &>/dev/null
-      if [ ! -f ./appinfo/info.xml ]; then
-        echo "appinfo/info.xml doesn't exist in $out, aborting!"
-        exit 1
-      fi
-      popd &>/dev/null
-    '';
     meta = {
       license = lib.licenses.${license};
       longDescription = description;
@@ -31,6 +24,12 @@ applyPatches ({
       inherit homepage;
     };
   };
+  prePatch = ''
+    if [ ! -f ./appinfo/info.xml ]; then
+      echo "appinfo/info.xml doesn't exist in $out, aborting!"
+      exit 1
+    fi
+  '';
 } // lib.optionalAttrs (appName != null && appVersion != null) {
   name = "nextcloud-app-${appName}-${appVersion}";
 })