Followup from renamin 'master' to 'main' for cf-deployment
Followup from renamin 'master' to 'main' for cf-deployment

* also remove 'branch' from concourse git resource since default branch
should be used

[#173736483](https://www.pivotaltracker.com/story/show/173736483)

Co-authored-by: Renee Chu <dbb10253d556b7398455fa674afa4c4a5a96979a@vmware.com>

pivotal-cf-experimental/bosh-bootloader,pivotal-cf-experimental/bosh-bootloader