Fix to prevent crashes

vines/functions.lua

@@ -32,7 +32,7 @@ vines.register_vine = function( name, defs, biome )
     sunlight_propagates = true,
     paramtype = "light",
     paramtype2 = "wallmounted",
-    buildable_to = true,
+    buildable_to = false,
     tiles = { vine_image_end },
     drawtype = drawtype,
     inventory_image = vine_image_end,
@@ -70,7 +70,7 @@ vines.register_vine = function( name, defs, biome )
     sunlight_propagates = true,
     paramtype = "light",
     paramtype2 = "wallmounted",
-    buildable_to = true,
+    buildable_to = false,
     tiles = { vine_image_middle },
     wield_image = vine_image_middle,
     drawtype = drawtype,