[Paheal] File extension is missing for some posts

[taskhawk]

I don't know if this is related to the warning they are currently displaying in posts:

Some images are temporarily broken due to server migration.

But some posts are using a new CDN that uses image URLs without file extensions and thus the extension keyword ends up empty.

Examples (NSFW):

https://rule34.paheal.net/post/view/3067

>$ gallery-dl -K "https://rule34.paheal.net/post/view/3067"
[...]
extension
  
file_url
  https://r34i.paheal-cdn.net/51/a5/51a5bc74b512b47a955a40809c72fe8d
[...]

https://rule34.paheal.net/post/view/5393822

>$ gallery-dl -K "https://rule34.paheal.net/post/view/5393822"
[...]
extension
  jpg
file_url
  https://lotus.paheal.net/_images/2b33b95e1fc4d034c773354ccf697ef6/5393822%20-%20Christmas%20featured_image%20saagelius%20Santa_Claus.jpg
[...]

The usual URLs appear to be available on the Links (File Only & Backup Server) section of the page though, maybe they should be used instead.

The Info section has the extension data easily available too, but doesn't seem to be used for anything when extracted so it can't be used as an alternative in case extension from the filename is empty, like {extension|ext} or something. I also found a bug there, the end delimiter should be < instead of >.

gallery-dl/gallery_dl/extractor/paheal.py

Line 62 in 6840717

dimensions, size, ext = extr("Info</th><td>", ">").split(" // ")