Fix fix_priv_tables.test: make mysql_system_tables_fix.sql to not modify...

Fix fix_priv_tables.test: make mysql_system_tables_fix.sql to not modify user.password_expired column.

scripts/mysql_system_tables_fix.sql

@@ -631,6 +631,9 @@ UPDATE user SET Create_tablespace_priv = Super_priv WHERE @hadCreateTablespacePr
 ALTER TABLE user ADD plugin char(64) DEFAULT '',  ADD authentication_string TEXT;
 ALTER TABLE user ADD password_expired ENUM('N', 'Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL;
 ALTER TABLE user MODIFY plugin char(64) CHARACTER SET latin1 DEFAULT '' NOT NULL, MODIFY authentication_string TEXT NOT NULL;
+-- Somewhere above, we ran ALTER TABLE user .... CONVERT TO CHARACTER SET utf8 COLLATE utf8_bin.
+--  we want password_expired column to have collation utf8_general_ci.
+ALTER TABLE user MODIFY password_expired ENUM('N', 'Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL;
 
 -- Need to pre-fill mysql.proxies_priv with access for root even when upgrading from
 -- older versions