test: fix replica's replication_timeout in replication suite

The value of box.cfg.replication_timeout should be the same on all
members of a cluster, otherwise replication may stop on timeout.
Since master.lua has box.cfg.replication_timeout set to 0.1, we should
use the same value in all replica scripts.

This fixes replication/wal_rw_stress test sporadic failure.

Closes #3885