fix testsuite false positive

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Bump version to 1.21.0

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Start 1.22.0 development cycle

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Merge git://busybox.net/busybox