Unblacklist a blacklisted tracker (at job level)?

[David Rosenstrauch]

I'm currently running a long-running job.  One of our nodes was 
misconfigured, however, and so got blacklisted in the job.

I've since corrected the problem, though, and restarted the tasktracker. 
 But how can I "un-blacklist" the tasktracker so that the job starts 
using it again?

TIA,

DR