Fix minus character (-) being stripped from signs (#3210)

Author: Desour

mods/default/nodes.lua

@@ -2620,7 +2620,7 @@ local function register_sign(material, desc, def)
 				minetest.chat_send_player(player_name, S("Text too long"))
 				return
 			end
-			text = text:gsub("[%z-\8\11-\31\127]", "") -- strip naughty control characters (keeps \t and \n)
+			text = text:gsub("[%z\1-\8\11-\31\127]", "") -- strip naughty control characters (keeps \t and \n)
 			default.log_player_action(sender, ("wrote %q to the sign at"):format(text), pos)
 			local meta = minetest.get_meta(pos)
 			meta:set_string("text", text)