SVNPoller log msg missing argument

[thatch]

This is around line 239 in buildbot.changes.svnpoller:

        if self.working:
            log.msg("SVNPoller(%s) overrun: timer fired but the previous "
                    "poll had not yet finished.")

I haven't seen an error triggered but it looks like there's a %s missing its corresponding % self.svnurl format argument.

[warner]

fixed, thanks!