Revert manga title folder for saved pages (closes #4803)

People also didn't like it making their galleries more complicate to navigate.

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderPresenter.kt

@@ -559,8 +559,7 @@ class ReaderPresenter(
         val destDir = File(
             Environment.getExternalStorageDirectory().absolutePath +
                 File.separator + Environment.DIRECTORY_PICTURES +
-                File.separator + context.getString(R.string.app_name) +
-                File.separator + manga.title
+                File.separator + context.getString(R.string.app_name)
         )
 
         // Copy file in background.