BUG/MINOR: ssl: trailing slashes in directory names wrongly cached

BUG/MINOR: ssl: trailing slashes in directory names wrongly cached

The crtlist_load_cert_dir() caches the directory name without trailing
slashes when ssl_sock_load_cert_list_file() tries to lookup without
cleaning the trailing slashes.

This bug leads to creating the crtlist twice and prevents to remove
correctly a crtlist_entry since it exists in the serveral crtlists
created by accident.

Move the trailing slashes cleanup in ssl_sock_load_cert_list_file() to
fix the problem.

This bug was introduced by 6be66ec ("MINOR: ssl: directories are loaded
like crt-list")