fix: sysVer of older CentOS

lib/data/model/server/conn_status.dart

@@ -0,0 +1,39 @@
+import '../../../core/extension/stringx.dart';
+import '../../res/misc.dart';
+
+///
+/// Code generated by jsonToDartModel https://ashamp.github.io/jsonToDartModel/
+///
+class ConnStatus {
+/*
+{
+  "maxConn": 0,
+  "active": 1,
+  "passive": 2,
+  "fail": 3
+} 
+*/
+
+  late int maxConn;
+  late int active;
+  late int passive;
+  late int fail;
+
+  ConnStatus(
+    this.maxConn,
+    this.active,
+    this.passive,
+    this.fail,
+  );
+}
+
+ConnStatus? parseConn(String raw) {
+  final lines = raw.split('\n');
+  final idx = lines.lastWhere((element) => element.startsWith('Tcp:'),
+      orElse: () => '');
+  if (idx != '') {
+    final vals = idx.split(numReg);
+    return ConnStatus(vals[5].i, vals[6].i, vals[7].i, vals[8].i);
+  }
+  return null;
+}