MDEV-10429: sys_vars.sysvars_wsrep fails in buildbot on host 'work' (valgrind builder)

- Fixed the test
- Improved comment for wsrep_drupal_282555_workaround

mysql-test/suite/sys_vars/r/sysvars_wsrep.result

@@ -162,7 +162,7 @@ GLOBAL_VALUE_ORIGIN	COMPILE-TIME
 DEFAULT_VALUE	OFF
 VARIABLE_SCOPE	GLOBAL
 VARIABLE_TYPE	BOOLEAN
-VARIABLE_COMMENT	To use a workaround forbad autoincrement value
+VARIABLE_COMMENT	Enable a workaround to handle the cases where inserting a DEFAULT value into an auto-increment column could fail with duplicate key error
 NUMERIC_MIN_VALUE	NULL
 NUMERIC_MAX_VALUE	NULL
 NUMERIC_BLOCK_SIZE	NULL

mysql-test/suite/sys_vars/t/sysvars_wsrep.test

@@ -3,7 +3,9 @@
 --let $datadir = `SELECT @@datadir`
 --let $hostname = `SELECT @@hostname`
 
---replace_result $datadir DATADIR $hostname HOSTNAME
+--replace_result $datadir DATADIR
+--let $hostname_regex=/^$hostname\$/HOSTNAME/
+--replace_regex $hostname_regex
 --vertical_results
 select * from information_schema.system_variables
   where variable_name like 'wsrep%'

sql/sys_vars.cc

@@ -4782,8 +4782,9 @@ static Sys_var_mybool Sys_wsrep_auto_increment_control(
        CMD_LINE(OPT_ARG), DEFAULT(TRUE));
 
 static Sys_var_mybool Sys_wsrep_drupal_282555_workaround(
-       "wsrep_drupal_282555_workaround", "To use a workaround for"
-       "bad autoincrement value", 
+       "wsrep_drupal_282555_workaround", "Enable a workaround to handle the "
+       "cases where inserting a DEFAULT value into an auto-increment column "
+       "could fail with duplicate key error",
        GLOBAL_VAR(wsrep_drupal_282555_workaround),
        CMD_LINE(OPT_ARG), DEFAULT(FALSE));