Consistently use trigger_avaproofs in abc_p2p_avalanche_remote_proofs

Summary: Noticed while debugging.

Test Plan:

./test/functional/test_runner.py abc_p2p_avalanche_remote_proofs

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Differential Revision: https://reviews.bitcoinabc.org/D15324