Describe the bug
When manually downloading subtitles I noticed that whenever I pick a subtitle, the page refreshes, but the subtitles are not applied.
I can upload the subtitles manually and that works fine.
Technical background: endpoint "manual_get_subtitle" returns error "413 Request Entity Too Large" so I assume that the uplaoded base64 is too large.
Is there any option to configure max body size? Not sure if it's CherryPy or Bottle that needs the change.
The subtitles file that causes problems is that one: http://napiprojekt.pl/unit_napisy/dl.php?nick=&f=6d2d743a7e27564e25f4fc6b09c29109&kolejka=false&t=84b05&napios=Linux&v=dreambox&pass=&l=PL (filename 6d2d743a7e27564e25f4fc6b09c29109).

To Reproduce
Steps to reproduce the behavior:

1. Go to episode X
2. Click on 'Manual search'
3. Click on download icon next to the subtitles
4. The page refreshes and subtitles are not applied

Expected behavior
The subtitles are downloaded and stored on disk.

Screenshots

Software (please complete the following information):

• Bazarr: 0.8.2.4
• OS: Linux, Docker (QNAP NAS)

Additional context