fix sporadic failures of main.processlist_notembedded

the test was doing

--replace_result $con_id con_id
eval SHOW EXPLAIN FOR $con_id;

with the intention of replacing the variable part of the statement
in the result log. But actually replace_result replaces everything
that matches. In particular, when $con_id is 100, the warning

Note   1003    select sleep(100000)

becomes

Note   con_id3    select sleep(con_id000)

1 files changed, 10 insertions, 10 deletions

diff --git a/mysql-test/main/processlist_notembedded.test b/mysql-test/main/processlist_notembedded.test
index 26021040c39..cc577200368 100644
--- a/mysql-test/main/processlist_notembedded.test
+++ b/mysql-test/main/processlist_notembedded.test
@@ -7,7 +7,7 @@ source include/count_sessions.inc;
 --echo # MDEV-20466: SHOW PROCESSLIST truncates query text on \0 bytes
 --echo #
 
-connect (con1,localhost,root,,);
+connect con1,localhost,root;
 
 connection con1;
 
@@ -39,22 +39,22 @@ SET DEBUG_SYNC = 'RESET';
 
 source include/wait_until_count_sessions.inc;
 
---echo End of 5.5 tests
+--echo #
+--echo # End of 5.5 tests
+--echo #
 
 --echo #
 --echo # MDEV-23752: SHOW EXPLAIN FOR thd waits for sleep
 --echo #
 
---connect (con1,localhost,root,,)
+--connect con1,localhost,root
 --let $con_id = `SELECT CONNECTION_ID()`
---send select sleep(100000);
+--send select sleep(100000)
 
 --connection default
+evalp SHOW EXPLAIN FOR $con_id;
+evalp KILL QUERY $con_id;
 
---replace_result $con_id con_id
-eval SHOW EXPLAIN FOR $con_id;
-
---replace_result $con_id con_id
-eval KILL QUERY $con_id;
-
+--echo #
 --echo # End of 10.2 tests
+--echo #