joplin: clean up dependencies

vips now propagates the requirements correctly

pkgs/development/node-packages/default-v10.nix

@@ -115,12 +115,9 @@ nodePackages // {
   joplin = nodePackages.joplin.override {
     nativeBuildInputs = [ pkgs.pkg-config ];
     buildInputs = with pkgs; [
-      # sharp, dep list:
-      # http://sharp.pixelplumbing.com/en/stable/install/
-      cairo expat fontconfig freetype fribidi gettext giflib
-      glib harfbuzz lcms libcroco libexif libffi libgsf
-      libjpeg_turbo libpng librsvg libtiff vips
-      libwebp libxml2 pango pixman zlib
+      # required by sharp
+      # https://sharp.pixelplumbing.com/install
+      vips
 
       nodePackages.node-pre-gyp
     ];