package/libcurl: fix missing CA bundle when wolfssl is SSL/TLS provider

Without CA bundle curl can not verify the remote peer and work with https.
This is fixed by adding a config option pointing to the default location
for CA bundle in buildroot. Alternatives like OpenSSL and MbedTLS use the
same path, however the wolfSSL build options for libcurl did not include
this path until now.

Signed-off-by: Dimitar Tomov <dimi@tpm.dev>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>