Unpin puppet-ssh_keygen

The puppet-ssh_keygen module has been pinned to the quite old version
but the pin is not necessary. This change removes the pin and bumps
the version to the current latest version.

Related-Bug: #1986651
Change-Id: I9dc0ab4f542248f82d036b78d84d9bc280036771

Puppetfile

@@ -216,7 +216,7 @@ mod 'corosync',
 
 mod 'ssh_keygen',
   :git => 'https://github.com/voxpupuli/puppet-ssh_keygen',
-  :ref => 'v2.0.1'
+  :ref => 'v5.0.2'
 
 mod 'redis',
   :git => 'https://github.com/voxpupuli/puppet-redis',

external_modules.txt

@@ -15,5 +15,5 @@ saz/puppet-memcached
 theforeman/puppet-dns
 voxpupuli/puppet-archive
 voxpupuli/puppet-corosync,v8.0.0
-voxpupuli/puppet-ssh_keygen,v2.0.1
+voxpupuli/puppet-ssh_keygen
 voxpupuli/puppet-redis