matrix: stream error received: unspecific protocol error detected

[LuckyTurtleDev]

import of some stickerpacks fail:

 ERROR failed to import sticker 2 from pack "TheLittleMole"

Caused by:
    0: error sending request for url (https://matrix-client.matrix.org/_matrix/media/r0/upload?access_token=TOKEN&filename=stickers%2Ffile_3643.webp): http2 error: stream error received: unspecific protocol error detected
    1: http2 error: stream error received: unspecific protocol error detected
    2: stream error received: unspecific protocol error detected
 ERROR failed to import sticker 7 from pack "TheLittleMole"

packs: https://t.me/addstickers/TheLittleMole, https://t.me/addstickers/ArcticFox