MDEV-5539 Empty results in UNION with Sphinx engine

The bug was fixed by Serg earlier by including Sphinx 2.2.6, but he forgot to update the test case.

storage/sphinx/mysql-test/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: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
+1	1	;mode=extended2;limit=1000000;maxmatches=500
+2	1	;mode=extended2;limit=1000000;maxmatches=500
+3	1	;mode=extended2;limit=1000000;maxmatches=500
+4	1	;mode=extended2;limit=1000000;maxmatches=500
 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;
 id	w	query
 1	1	;mode=extended2;limit=1000000;maxmatches=500

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

@@ -5,11 +5,6 @@
 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 $q2=SELECT * FROM ts si WHERE si.query='@* 123nothingtofind123;mode=extended2;limit=1000000;maxmatches=500';
-########################
-# BUG BUG BUG !!!
-# Note, the result below is incorrect! It should be updated when
-# MDEV-5539 is fixed upstream!!!
-########################
 eval SELECT a.* FROM ($q1) AS a UNION SELECT b.* FROM ($q2) AS b;
 eval SELECT a.* FROM ($q2) AS a UNION SELECT b.* FROM ($q1) AS b;
 drop table ts;