test: use unix socket in replication-py tests

To reduce the chance to encounter the tarantool/test-run#141 issue in
replication-py tests, let's switch to using unix sockets instead of TCP
ports for tarantool console.

NO_DOC=testing stuff
NO_TEST=testing stuff
NO_CHANGELOG=testing stuff

(cherry picked from commit cb6fc4a)

Author: ylobankov

test/replication-py/suite.ini

@@ -2,6 +2,7 @@
 core = tarantool
 script =  master.lua
 description = tarantool/box, replication
+use_unix_sockets = True
 is_parallel = True
 fragile = {
     "retries": 10,