fix the test

mysql-test/suite/sphinx/union-5539.result

-create table ts (id bigint unsigned not null, w int not null, query varchar(255) not null, index(query)) engine=sphinx connection="sphinx://127.0.0.1:16002/*";
+create table ts (id bigint unsigned not null, w int not null, query varchar(255) not null, index(query)) engine=sphinx connection="sphinx://127.0.0.1:PORT/*";
 SELECT a.* FROM (SELECT * FROM ts si WHERE si.query=';mode=extended2;limit=1000000;maxmatches=500') AS a UNION SELECT b.* FROM (SELECT * FROM ts si WHERE si.query='@* 123nothingtofind123;mode=extended2;limit=1000000;maxmatches=500') AS b;
 id	w	query
 SELECT a.* FROM (SELECT * FROM ts si WHERE si.query='@* 123nothingtofind123;mode=extended2;limit=1000000;maxmatches=500') AS a UNION SELECT b.* FROM (SELECT * FROM ts si WHERE si.query=';mode=extended2;limit=1000000;maxmatches=500') AS b;

mysql-test/suite/sphinx/union-5539.test

 #
 # MDEV-5539 Empty results in UNION with Sphinx engine
 #
+--replace_result $SPHINXSEARCH_PORT PORT
 eval create table ts (id bigint unsigned not null, w int not null, query varchar(255) not null, index(query)) engine=sphinx connection="sphinx://127.0.0.1:$SPHINXSEARCH_PORT/*";
 let $q1=SELECT * FROM ts si WHERE si.query=';mode=extended2;limit=1000000;maxmatches=500';
 let $q2=SELECT * FROM ts si WHERE si.query='@* 123nothingtofind123;mode=extended2;limit=1000000;maxmatches=500';