Merge pull request #2096 from 821938089/fix-readbook-config-restore-bug

修复文字颜色和背景恢复预设可能会无效的bug

app/src/main/java/io/legado/app/ui/book/read/config/BgTextConfigDialog.kt

@@ -160,7 +160,7 @@ class BgTextConfigDialog : BaseDialogFragment(R.layout.dialog_read_bg_text) {
             val layoutNames = defaultConfigs.map { it.name }
             context?.selector("选择预设布局", layoutNames) { _, i ->
                 if (i >= 0) {
-                    ReadBookConfig.durConfig = defaultConfigs[i]
+                    ReadBookConfig.durConfig = defaultConfigs[i].copy()
                     initData()
                     postEvent(EventBus.UP_CONFIG, true)
                 }