upgrade & opt

- flutter 3.0.1
- show snackbar when no server to ping
- server detail page replace nice to iowait
- make script show stdout when error

lib/generated/intl/messages_en.dart

@@ -148,6 +148,8 @@ class MessageLookup extends MessageLookupByLibrary {
         "pingAvg": MessageLookupByLibrary.simpleMessage("Avg:"),
         "pingInputIP": MessageLookupByLibrary.simpleMessage(
             "Please input a target IP/domain."),
+        "pingNoServer": MessageLookupByLibrary.simpleMessage(
+            "No server to ping.\nPlease add a server in server tab."),
         "platformNotSupportUpdate": MessageLookupByLibrary.simpleMessage(
             "Current platform does not support in app update.\nPlease build from source and install it."),
         "plzEnterHost":

lib/generated/intl/messages_zh.dart

@@ -130,6 +130,8 @@ class MessageLookup extends MessageLookupByLibrary {
         "ping": MessageLookupByLibrary.simpleMessage("Ping"),
         "pingAvg": MessageLookupByLibrary.simpleMessage("平均:"),
         "pingInputIP": MessageLookupByLibrary.simpleMessage("请输入目标IP或域名"),
+        "pingNoServer": MessageLookupByLibrary.simpleMessage(
+            "没有服务器可用于Ping\n请在服务器tab添加服务器后再试"),
         "platformNotSupportUpdate":
             MessageLookupByLibrary.simpleMessage("当前平台不支持更新，请编译最新源码后手动安装"),
         "plzEnterHost": MessageLookupByLibrary.simpleMessage("请输入主机"),

lib/generated/l10n.dart

@@ -1220,6 +1220,16 @@ class S {
       args: [],
     );
   }
+
+  /// `No server to ping.\nPlease add a server in server tab.`
+  String get pingNoServer {
+    return Intl.message(
+      'No server to ping.\nPlease add a server in server tab.',
+      name: 'pingNoServer',
+      desc: '',
+      args: [],
+    );
+  }
 }
 
 class AppLocalizationDelegate extends LocalizationsDelegate<S> {