Support --tracker from transmission's TR_TORRENT_TRACKERS

[sentriz]

hi, transmission's on complete script automatically sets TR_TORRENT_TRACKERS, TR_TORRENT_DIR, TR_TORRENT_NAME, and TR_TORRENT_HASH

i want to use it like this

RED_API_KEY=123 \
OPS_API_KEY=123 \
gazelle-origin \
  --tracker "$TR_TORRENT_TRACKERS" \
  --out "$TR_TORRENT_DIR/$TR_TORRENT_NAME/origin.yaml" \
  "$TR_TORRENT_HASH"

but it only works if gazelle-origin understands trackers like flacsfor.me:443 which is what TR_TORRENT_TRACKERS contains

thanks!