[MINOR] move the initial task's nice value to the listener

Since the listener is the one indicating what analyser and session
handlers to call, it makes sense that it also sets the task's nice
value. This also helps getting rid of the last trace of the stats
in the proto_uxst file.
diff --git a/src/client.c b/src/client.c
index 93bd894..b2e7d78 100644
--- a/src/client.c
+++ b/src/client.c
@@ -1,7 +1,7 @@
 /*
  * Client-side variables and functions.
  *
- * Copyright 2000-2008 Willy Tarreau <w@1wt.eu>
+ * Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -173,6 +173,7 @@
 
 		t->process = l->handler;
 		t->context = s;
+		t->nice = l->nice;
 
 		s->task = t;
 		s->listener = l;