Don't double-encode file title

Author: SamantazFox

src/invidious/routes/video_playback.cr

@@ -164,7 +164,9 @@ module Invidious::Routes::VideoPlayback
 
               if title = query_params["title"]?
                 # https://blog.fastmail.com/2011/06/24/download-non-english-filenames/
-                env.response.headers["Content-Disposition"] = "attachment; filename=\"#{URI.encode_www_form(title)}\"; filename*=UTF-8''#{URI.encode_www_form(title)}"
+                filename = URI.encode_www_form(title, space_to_plus: false)
+                header = "attachment; filename=\"#{filename}\"; filename*=UTF-8''#{filename}"
+                env.response.headers["Content-Disposition"] = header
               end
 
               if !resp.headers.includes_word?("Transfer-Encoding", "chunked")

src/invidious/routes/watch.cr

@@ -304,12 +304,9 @@ module Invidious::Routes::Watch
     end
 
     download_widget = JSON.parse(selection)
-    extension = download_widget["ext"].as_s
 
-    filename = URI.encode_www_form(
-      "#{video_id}-#{title}.#{extension}",
-      space_to_plus: false
-    )
+    extension = download_widget["ext"].as_s
+    filename = "#{video_id}-#{title}.#{extension}"
 
     # Pass form parameters as URL parameters for the handlers of both
     # /latest_version and /api/v1/captions. This avoids an un-necessary