test: avoid non-determinism in asmap-addrman test
Summary:
The probability of collision when adding an addrman entry is expected to be 1/2^16 = 1/65536 for an address from a different /16. This change hopes to avoid these collisions by adding 1 tried entry before adding 1 new table one, instead of 2 tried entries followed by 2 new entries, which appears to have caused a collision in the CI.
Backport of core#23084.
Test Plan:
In a loop:
./test/functional/test_runner.py feature_asmap
Reviewers: #bitcoin_abc, PiRK
Reviewed By: #bitcoin_abc, PiRK
Differential Revision: https://reviews.bitcoinabc.org/D12363