BUG/MEDIUM: ssl/cli: 'commit ssl cert' crashes when no private key

A crash was reported in issue #707 because the private key was not
uploaded correctly with "set ssl cert".

The bug is provoked by X509_check_private_key() being called when there
is no private key, which can lead to a segfault.

This patch adds a check and return an error is the private key is not
present.

This must be backported in 2.1.
1 file changed