Fix sheep wool farm crash

mods/ITEMS/REDSTONE/mesecons/actionqueue.lua

@@ -89,6 +89,8 @@ minetest.register_globalstep(function (dtime)
 end)
 
 function mesecon.queue:execute(action)
+	if not action.pos then return end
+	
 	-- ignore if action queue function name doesn't exist,
 	-- (e.g. in case the action queue savegame was written by an old mesecons version)
 	if mesecon.queue.funcs[action.func] then

mods/ITEMS/REDSTONE/mesecons/internal.lua

@@ -521,6 +521,7 @@ end
 -- outputnode (receptor or conductor) at position `output` and has an output in direction `rule`
 function mesecon.rules_link_rule_all(output, rule)
 	local input = vector.add(output, rule)
+	if not input then return {} end
 	local inputnode = get_node_force(input)
 	local inputrules = mesecon.get_any_inputrules(inputnode)
 	if not inputrules then