libcanberra: fix .la file

pkgs/development/libraries/libcanberra/default.nix

···
 
   configureFlags = "--disable-oss";
 
+  postInstall = ''
+    for f in $out/lib/*.la; do
+      sed 's|-lltdl|-L${libtool}/lib -lltdl|' -i $f
+    done
+  '';
+
   passthru = {
     gtkModule = "/lib/gtk-2.0/";
   };