apostrophe: make texlive overrideable more easily

Now you can just build apostrophe.override { texlive = yourTexliveDist; }
which makes using a custom texlive distribution possible.

pkgs/applications/editors/apostrophe/default.nix

@@ -10,7 +10,6 @@ let
     regex setuptools python-Levenshtein pyenchant
     pygobject3 pycairo pypandoc chardet
   ]);
-  texliveDist = texlive.combined.scheme-medium;
 
 in stdenv.mkDerivation rec {
   pname = "apostrophe";
@@ -28,7 +27,7 @@ in stdenv.mkDerivation rec {
     appstream-glib wrapGAppsHook ];
 
   buildInputs = [ glib pythonEnv gobject-introspection gtk3
-    gnome3.adwaita-icon-theme webkitgtk gspell texliveDist
+    gnome3.adwaita-icon-theme webkitgtk gspell texlive
     glib-networking libhandy ];
 
   postPatch = ''
@@ -41,7 +40,7 @@ in stdenv.mkDerivation rec {
   preFixup = ''
     gappsWrapperArgs+=(
       --prefix PYTHONPATH : "$out/lib/python${pythonEnv.pythonVersion}/site-packages/"
-      --prefix PATH : "${texliveDist}/bin"
+      --prefix PATH : "${texlive}/bin"
       --prefix PATH : "${haskellPackages.pandoc-citeproc}/bin"
       --prefix XDG_DATA_DIRS : "${shared-mime-info}/share"
     )

pkgs/top-level/all-packages.nix

@@ -21297,6 +21297,7 @@ in
 
   apostrophe = callPackage ../applications/editors/apostrophe {
     pythonPackages = python3Packages;
+    texlive = texlive.combined.scheme-medium;
   };
 
   aqemu = libsForQt5.callPackage ../applications/virtualization/aqemu { };