Update UI Style

app/src/main/res/xml/pref_main.xml

@@ -12,7 +12,7 @@
         app:iconSpaceReserved="false" />
 
     <io.legado.app.lib.prefs.Preference
-        android:icon="@drawable/ic_cfg_source"
+        android:icon="@drawable/ic_cfg_txt"
         android:key="txtTocRuleManage"
         android:summary="@string/config_txt_toc_rule"
         android:title="@string/txt_toc_rule"
@@ -32,16 +32,6 @@
         android:title="@string/dict_rule"
         app:iconSpaceReserved="false" />
 
-    <io.legado.app.lib.prefs.NameListPreference
-        android:defaultValue="0"
-        android:entries="@array/theme_mode"
-        android:entryValues="@array/theme_mode_v"
-        android:icon="@drawable/ic_cfg_theme"
-        android:key="themeMode"
-        android:summary="@string/theme_mode_desc"
-        android:title="@string/theme_mode"
-        app:iconSpaceReserved="false" />
-
     <io.legado.app.lib.prefs.SwitchPreference
         android:defaultValue="false"
         android:icon="@drawable/ic_cfg_web"