test/quicapitest.c: Increase timeout of test_fin_only_blocking to 40ms

test/quicapitest.c: Increase timeout of test_fin_only_blocking to 40ms

Running this test on heavily loaded systems may cause the SSL_read_ex() to
take more than 20ms, due to concurrent workload.

Increase the timeout to 40ms to allow a little bit more time.

Signed-off-by: Ingo Franzki <ifranzki@linux.ibm.com>
Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/26693)