Fix some badly written Galera tests

galera.galera_kill_applier: Make the test less likely to fail
by adding sleep time.

galera.query_cache: Remove data truncation.

Part of the test file looks like it has been misinterpreted as latin1
and wrongly converted to UTF-8 encoding. In MariaDB 10.1, the server would
only warn about data truncation and not issue an error. 10.2 is stricter.
(The test should be carefully reviewed if it really makes sense.)

mysql-test/suite/galera/t/galera_kill_applier.test

@@ -6,7 +6,7 @@
 --source include/have_innodb.inc
 
 --connection node_1
---sleep 1
+--sleep 2
 --let $applier_thread = `SELECT ID FROM INFORMATION_SCHEMA.PROCESSLIST WHERE USER = 'system user' AND STATE IS NULL LIMIT 1`
 
 --disable_query_log

mysql-test/suite/galera/t/query_cache.test

@@ -323,7 +323,7 @@ drop table t1;
 --echo # On node-1
 --connection node_1
 create table t1 (a char(1) not null collate koi8r_general_ci) engine=innodb;
-insert into t1 values(_koi8r"á");
+insert into t1 values(_koi8r 0xc3);
 set CHARACTER SET koi8r;
 select * from t1;
 set CHARACTER SET cp1251_koi8;
@@ -861,7 +861,7 @@ drop table t1;
 --connection node_1
 SET NAMES koi8r;
 CREATE TABLE t1 (a char(1) character set koi8r) engine=innodb;
-INSERT INTO t1 VALUES (_koi8r'á'),(_koi8r'Á');
+INSERT INTO t1 VALUES (_koi8r 0xc3),(_koi8r 0xc3);
 #
 # Run select
 #