fix two nil errors

awesome/src/modules/notification-center/status_bars.lua

@@ -346,6 +346,7 @@ return function()
         capi.awesome.connect_signal(
           "update::gpu_usage",
           function(gpu_usage)
+            if not gpu_usage then return end
             tooltip.text = "GPU Usage: " .. gpu_usage .. "%"
             rubato_timer.target = tonumber(gpu_usage)
           end

awesome/src/tools/helpers/cpu_temp.lua

@@ -14,6 +14,7 @@ watch(
       awful.spawn.easy_async_with_shell(
         "paste <(cat /sys/class/thermal/thermal_zone*/type) <(cat /sys/class/thermal/thermal_zone*/temp)",
         function(stdout2)
+          if (not stdout2) or stdout:match("\n") then return end
           temp = math.floor((tonumber(stdout2:match("x86_pkg_temp(.%d+)")) / 1000) + 0.5)
           capi.awesome.emit_signal(
             "update::cpu_temp",