remove n-sch from the watch list

we've seen no n-sch errors in passing gate runs in the last week,
I consider this sufficient proof that we're clean on n-sch for now.

Part of bp:clean-logs

Change-Id: Ife0e0602767e155fc645e07546bed36c2c060a20
diff --git a/tools/check_logs.py b/tools/check_logs.py
index b5b1780..bc4eaca 100755
--- a/tools/check_logs.py
+++ b/tools/check_logs.py
@@ -46,7 +46,6 @@
     'n-api',
     'n-cpu',
     'n-net',
-    'n-sch',
     'q-agt',
     'q-dhcp',
     'q-lbaas',