fix(jellyfin-api): use standard Authorization header (#2211)

Replace X-Emby-Authorization with Authorization header to fix authentication failures when users
have <EnableLegacyAuthorization>false</EnableLegacyAuthorization> in their Jellyfin system.xml.

server/api/jellyfin.ts

@@ -145,7 +145,7 @@ class JellyfinAPI extends ExternalAPI {
       {},
       {
         headers: {
-          'X-Emby-Authorization': authHeaderVal,
+          Authorization: authHeaderVal,
           'Content-Type': 'application/json',
           Accept: 'application/json',
         },