Fix crash when digging nodes with fishing rod

Previously the game would crash when digging nodes with a tool which
does not have tool_capabilities in their item definition.

mods/CORE/_mcl_autogroup/init.lua

@@ -178,6 +178,10 @@ end
 -- Add the groupcaps from a field in "_mcl_diggroups" to the groupcaps of a
 -- tool.
 local function add_groupcaps(toolname, groupcaps, groupcaps_def, efficiency)
+	if not groupcaps_def then
+		return
+	end
+
 	for g, capsdef in pairs(groupcaps_def) do
 		local mult = capsdef.speed or 1
 		local uses = capsdef.uses
@@ -196,7 +200,6 @@ local function add_groupcaps(toolname, groupcaps, groupcaps_def, efficiency)
 			groupcaps[g .. "_dig"] = get_groupcap(g, level > 0, mult, efficiency, uses)
 		end
 	end
-	return groupcaps
 end
 
 -- Checks if the given node would drop its useful drop if dug by a given tool.

mods/ITEMS/mcl_enchanting/groupcaps.lua

@@ -45,6 +45,10 @@ end
 -- To make it more efficient it will first check a hash value to determine if
 -- the tool needs to be updated.
 function mcl_enchanting.update_groupcaps(itemstack)
+	if not itemstack:get_meta():get("tool_capabilities") then
+		return
+	end
+
 	local name = itemstack:get_name()
 	local level = mcl_enchanting.get_enchantment(itemstack, "efficiency")
 	local groupcaps = get_efficiency_groupcaps(name, level)