Adjust Open vSwitch mailing lists to reflect reality

Adjust Open vSwitch mailing lists to reflect reality

We've gone through a couple of iterations for names of these mailing
lists.  Currently, there are three: announce, discuss, and git.  There
are aliases that point "bugs" and "dev" to the "discuss" mailing list.
This commit drops the "ovs-" prefix to mailing lists, since we're not
using them.