Revert "[FIX] Enabling passthru with transcoding"

This reverts commit 2f4af332dd8a14abd89a1fb27b40c5db01b8efdf.
Revert "[FIX] http protocol rather than plexsever as URL is being translated before"

This reverts commit 4ac6a95a82347a6129e9fc2c748440f49e8de096.
Ignore X-Plex-Client-Capabilities when constructing the transcoder URL.

This header is not used for the new transcoder, so it’s not a problem.
Also ffmpeg doesn’t like to parse URL’s with {} in it.
Also run our Mime detection stuff on transcoder url's.