Upgrading libvpx demands bash

[francesco scaglione]

After a portmaster -L I see that I need to upgrade libvpx, but now that
brings in bash:

# portmaster libvpx

===>>> The following actions will be taken if you choose to proceed:
	Upgrade libvpx-1.3.0 to libvpx-1.3.0_1
	Install shells/bash

I'm using a very small server (FreeBSD 8.4, amd64) and I would like to
avoid adding the bash port, if possible.

But maybe I cannot avoid it, can I?

Thanks,
Francesco