[SSSD] [sssd PR#901][opened] Update sss_ssh.c

[alexal]

   URL: https://github.com/SSSD/sssd/pull/901
Author: alexal
 Title: #901: Update sss_ssh.c
Action: opened

PR body:
"""
SSH: Adds a message to the syslog if an SSH key is malformed

If an SSH key contains trailing whitespace (or newlines), it will be considered as
malformed by sss_ssh_format_pubkey() function. With the current version the only way to
detect that problem is to enable --debug option for /usr/bin/sss_ssh_authorizedkeys
utility. I'm adding an additional message to the syslog which will help to determine
such problems without enabling debug.

Resolves: https://pagure.io/SSSD/sssd/issue/3864
"""

To pull the PR as Git branch:
git remote add ghsssd https://github.com/SSSD/sssd
git fetch ghsssd pull/901/head:pr901
git checkout pr901