BUG #15376: Postgres sql 9.4.19 pg_upgrade stops with error Thesource cluster was not shut down cleanly.

The following bug has been logged on the website:

Bug reference:      15376
Logged by:          kalyani kaniganti
Email address:      kalyanithumati@gmail.com
PostgreSQL version: 9.4.19
Operating system:   SUSE LINUX
Description:

Currently, we are using 9.4.17 version of Postgre SQL and due to the
security vulnerabilities reported(CVE-2018-10925,
CVE-2018-10915) we are upgrading the Postgres SQL to 9.4.19 version as the
fixes are available.
 The application started up successfully with 9.4.19 version and DB
transactions are working fine, But we are facing issues when upgrading the
database from 9.1 version to latest version 9.4.19.
pg_upgrade is failing and throwing the below error.
The source cluster was not shut down cleanly.
Failure, exiting
ERROR: DB upgrade failed! 
From some of the sites and Postgre SQL.org, we have noticed that this error
occurs when an old server doesn't shut down properly and pg_upgarde is
failing to check that and in 9.4.19 version release notes mentioned that
this issue is fixed.
But still we are facing the error, Could anyone of you can share the details
that issue is fixed in 9.4.19 and suggest how we can proceed further to
resolve this issue.