Ignore unreadable SSH private keys when autoloading identities
During SSH startup we read all keys in the user's ~/.ssh, even
if we may not need them for this particular transport session.
If a file is not really a key, or it contains a key that JSch
doesn't recognize we shouldn't crash the transport. Instead
we should skip the file and move on. Later on we just don't
have that identity available to us, or we'll crash if we try
to add that identity file explicitly from ~/.ssh/config.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>