If checked, the initial checkout step will not avoid the second fetch. Git plugin versions prior to git plugin 4.4 would perform two fetch operations during the initial repository checkout. Git plugin 4.4 removes the second fetch operation in most cases. Enabling this option will restore the second fetch operation.
This setting is only needed if there is a bug in the redundant fetch removal logic. If you enable this setting, please report a git plugin issue that describes why you needed to enable it.