BUG#31880 make test failure from public bk tree
BUG#31880 make test failure from public bk tree


mysql-test/mysql-test-run.pl:
  BUG#31880 make test failure from public bk tree
  
  Instead of handling "MTR_BUILD_THREAD set" and "MTR_BUILD_THREAD not set" differently, use the same subroutine to set up the port numbers. The addition of a second master apparently broke the old static port numbers.

ollie314/server,davidl-zend/zenddbi,davidl-zend/zenddbi,slanterns/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,ollie314/server,davidl-zend/zenddbi,davidl-zend/zenddbi,ollie314/server,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix,ollie314/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix,ollie314/server,flynn1973/mariadb-aix,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi