Plesk 11.5.30 for Linux post Update #26 error

During Plesk control panel version 11.5.30 for Linux when updated to #26 I got error:

ERROR: PleskFatalException: Unable to connect to database: mysql_connect(): No such file or directory (auth.php:142)

When I have checked KB articles related to this problem on suggested link Search for related Knowledge Base articles

I have found working solution:

# export PSA_PASSWORD='MySecurePleskPassword'
# /usr/local/psa/admin/bin/ch_admin_passwd