Remove nonfree tile data.

Note this does not remove the directories; ensure they are snippeted out separately.

Patch by bdunahu <bdunahu@operationnull.com>.

diff --git a/lib/tiles/list.txt b/lib/tiles/list.txt
index 3677ba45e..eb2592c9f 100644
--- a/lib/tiles/list.txt
+++ b/lib/tiles/list.txt
@@ -54,15 +48,3 @@
 size:16:16:8x16.png
 pref:graf-nmd.prf
 extra:0:0:0
-
-name:5:Shockbolt Dark
-directory:shockbolt
-size:64:64:64x64.png
-pref:graf-shb-dark.prf
-extra:1:27:31
-
-name:6:Shockbolt Light
-directory:shockbolt
-size:64:64:64x64.png
-pref:graf-shb-light.prf
-extra:1:27:31