git hash in drv_in not updated after case creation.

The git hash recorded in the drv_in namelist file seems to be set at whatever it was when the case was created.

That makes sense for production runs. However a typical development pattern is to create a feature branch, create a case for testing development, and then add commits on that feature branch, building and running with each change within the case first created. The hash in drv_in should change if the SRCROOT hash changes but it does not. Not even "case.setup --reset" will change it.