bug #19452 (mysql_upgrade reads [client] section but doesn't handle [host] option

client/mysql_upgrade.c:
  "client" group removed from the 'readlist'

client/mysql_upgrade.c

@@ -65,7 +65,7 @@ static struct my_option my_long_options[]=
 };
 static const char *load_default_groups[]=
 {
-  "mysql_upgrade", "client", 0
+  "mysql_upgrade", 0
 };
 
 #include <help_end.h>