#536 proper clearing of cleared config values

rtu/configure.lua

@@ -650,7 +650,8 @@ local function config_view(display)
 
     ---@param exclude_conns boolean? true to exclude saving peripheral/redstone connections
     local function save_and_continue(exclude_conns)
-        for k, v in pairs(tmp_cfg) do
+        for _, field in ipairs(fields) do
+            local k, v = field[1], tmp_cfg[field[1]]
             if not (exclude_conns and (k == "Peripherals" or k == "Redstone")) then
                 if v == nil then settings.unset(k) else settings.set(k, v) end
             end