x509-store: reduce number of pre-allocated hashtable buckets

x509-store: reduce number of pre-allocated hashtable buckets

pre-allocating too much hashtable objects to avoid the hashtable
regrowing is mistake, and had immediate impact on memory footprint.

Resolves: https://github.com/openssl/project/issues/1679
Link: https://openssl-library.org/performance/
Fixes: 04589b59ef50 ("x509store: reduce lock contention in X509_STORE")
Signed-off-by: Nikola Pajkovsky <nikolap@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/28965)