haskell-gtksourceview2: add override to fix build

Changed files
+1
pkgs
development
haskell-modules
+1
pkgs/development/haskell-modules/configuration-common.nix
···
glib = addPkgconfigDepend super.glib pkgs.glib;
gtk3 = super.gtk3.override { inherit (pkgs) gtk3; };
gtk = addPkgconfigDepend super.gtk pkgs.gtk;
+
gtksourceview2 = (addPkgconfigDepend super.gtksourceview2 pkgs.gtk2).override { inherit (pkgs.gnome2) gtksourceview; };
gtksourceview3 = super.gtksourceview3.override { inherit (pkgs.gnome3) gtksourceview; };
# Need WebkitGTK, not just webkit.