Say that bug4438 was a fix on 0.2.1.9-alpha.

Say that bug4438 was a fix on 0.2.1.9-alpha.

Specifically, it was a fix on 33e2053ebca5d, where we introduced the
WRA_* and ROUTER_* codes for dirserv_add_descriptor.  Previously, we
had checked for a _negative_ return from dirserv_add_descriptor, which
meant "rejected".  An insufficiently new descriptor would give a
0-valued return.  But when we switched from numbers to enums, we got
this check wrong and had init_keys() give an error whenever the
descriptor wasn't accepted.