Add some warning if server running in docker

lib/l10n/app_en.arb

@@ -142,5 +142,6 @@
     "keyIsExists": "Key is exists.",
     "redirectToFlutter": "Redirect to Flutter frontend when accessing the root URL.",
     "downloadTimeoutCheckInterval": "The interval of checking download timeout",
-    "downloadTimeoutCheckIntervalHelp": "The smaller the value, the more accurate the timeout detection, but the higher CPU usage."
+    "downloadTimeoutCheckIntervalHelp": "The smaller the value, the more accurate the timeout detection, but the higher CPU usage.",
+    "dockerHelper": "The server is running in a Docker container. Unless you know what you are doing, do not change this setting."
 }

lib/l10n/app_zh.arb

@@ -142,5 +142,6 @@
     "keyIsExists": "键已存在。",
     "redirectToFlutter": "访问根 URL 时重定向到 flutter 前端。",
     "downloadTimeoutCheckInterval": "下载超时检测间隔",
-    "downloadTimeoutCheckIntervalHelp": "值越小，检测准确性越高，但是消耗更多的 CPU。"
+    "downloadTimeoutCheckIntervalHelp": "值越小，检测准确性越高，但是消耗更多的 CPU。",
+    "dockerHelper": "服务器运行在 Docker 容器中。除非你知道你在做什么，否则不要修改这个设置。"
 }

lib/server_settings.dart

@@ -327,8 +327,9 @@ class _ServerSettingsPage extends State<ServerSettingsPage>
               decoration: InputDecoration(
                 border: const OutlineInputBorder(),
                 labelText: i18n.serverDbPath,
-                helperText:
-                    auth.isDocker == true ? null : i18n.serverDbPathHelp,
+                helperText: auth.isDocker == true
+                    ? i18n.dockerHelper
+                    : i18n.serverDbPathHelp,
               ),
               onChanged: (s) {
                 setState(() {
@@ -364,6 +365,7 @@ class _ServerSettingsPage extends State<ServerSettingsPage>
             decoration: InputDecoration(
               border: const OutlineInputBorder(),
               labelText: i18n.downloadLocation,
+              helperText: auth.isDocker == true ? i18n.dockerHelper : null,
             ),
             onChanged: (s) {
               setState(() {
@@ -499,6 +501,7 @@ class _ServerSettingsPage extends State<ServerSettingsPage>
             decoration: InputDecoration(
               border: const OutlineInputBorder(),
               labelText: i18n.ffmpegPath,
+              helperText: auth.isDocker == true ? i18n.dockerHelper : null,
             ),
             onChanged: (s) {
               setState(() {
@@ -534,6 +537,7 @@ class _ServerSettingsPage extends State<ServerSettingsPage>
             decoration: InputDecoration(
               border: const OutlineInputBorder(),
               labelText: i18n.thumbnailDir,
+              helperText: auth.isDocker == true ? i18n.dockerHelper : null,
             ),
             onChanged: (s) {
               setState(() {
@@ -616,6 +620,7 @@ class _ServerSettingsPage extends State<ServerSettingsPage>
             decoration: InputDecoration(
               border: const OutlineInputBorder(),
               labelText: i18n.flutterFrontend,
+              helperText: auth.isDocker == true ? i18n.dockerHelper : null,
             ),
             onChanged: (s) {
               setState(() {