Update to 2.4.3

Changelog:

• Fix panic when using custom EC2 API for SD
• Fix panic when Zookeeper SD cannot connect to servers
• Make the skip_head an optional parameter for snapshot API

PR: 232186
Submitted by: David O'Rourke <dor.bsd@xm0.uk> (maintainer)
Sponsored by: Netzkommune GmbH