uclient-fetch: use package name pattern in message for missing SSL library

uclient-fetch: use package name pattern in message for missing SSL library

When faced with this error message, I did not directly know what
package(s) to install. I first grepped the package list for packages
named libustream-ssl... found nothing, and finally realized, that here
only the library name was mentioned.

But when we mention the certificate packages, why not also directly
mention the SSL/TLS packages with a pattern. That will save one step
next time when stumbling here - at least for me ;-)

Signed-off-by: Michael Heimpold <mhei@heimpold.de>