Revert "dependencies: check that SSL certificates are installed"

This reverts commit d66cd067.

SSL certificates are no always installed in /etc/ssl/certs. For example, on
CentOS 5.6 the default OpenSSL certificates directory is /etc/pki/tls/certs,
and wget can download using https without any problem.

Moreover, the existence of /etc/ssl/certs does not guarantee the presence of a
CA certificates bundle even on Debian. On my current Debian testing
installation the openssl package itself creates an empty /etc/ssl/certs
directory.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>