Line number for files conventionally start with 1, but using for lineno, line in enumerate(f): would consider the first line to be line 0.
for lineno, line in enumerate(f):
Passing an initial value of 1 to enumerate will fix this line number.
Fix line number for known_hosts error messages.
Took me a while to realize that this only impacts log lines and not actual exceptions. 😩 One can reproduce the incorrect-line-number messages by enabling logging, mangling a known_hosts file so it includes lines like e.g. foo (vs foo ssh-rsa <key text>) and then calling e.g. SSHClient.load_system_host_keys.
foo ssh-rsa <key text>
Also, no idea why I punted this to 1.16.
Changelog closes #401