tweaking the congestion handler a bit

BackupPC_archiveHost_s3

@@ -120,6 +120,7 @@ class SlowFile:
         else:
             # we're late; something got slow.
             lateness = starttime - self.lastblocktargettime
+            if lateness > 0.2:
                 self.delayfactor += min(0.5, lateness)
                 logger.debug('%.2f seconds late (congestion?); setting delayfactor to %.2f' % (lateness, self.delayfactor))
 
@@ -129,7 +130,7 @@ class SlowFile:
         if time.time() > self.lastdebug+60:
             if self.delayfactor > 1:
                 # reduce the penalty a bit
-                self.delayfactor -= 0.1
+                self.delayfactor -= 0.2
                 targetspeed = self.speed/float(self.delayfactor)
                 self.lastblocktargettime = time.time() + len/float(targetspeed)