kdump initial ramdisk creation is failing when configured with remote ssh dump server

Issue

• We updated our system to Red Hat Enterprise Linux 7.4. After that, it's not possible to start kdump.

[root@foo ~]# systemctl status kdump
● kdump.service - Crash recovery kernel arming
   Loaded: loaded (/usr/lib/systemd/system/kdump.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Thu 2017-12-01 14:45:43 CET; 55s ago
  Process: 11206 ExecStart=/usr/bin/kdumpctl start (code=exited, status=1/FAILURE)
 Main PID: 11206 (code=exited, status=1/FAILURE)

Dec 07 14:45:42 foo.acme.com kdumpctl[11206]: No kdump initial ramdisk found.
Dec 07 14:45:42 foo.acme.com kdumpctl[11206]: Rebuilding /boot/initramfs-3.10.0-693.5.2.el7.x86_64kdump.img
Dec 07 14:45:43 foo.acme.com kdumpctl[11206]: checking remote ssh server available size failed.
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