cbuildbot: force people to use --remote/--local now

We've allowed along enough for people to transition to these flags.

BUG=None
TEST=`cbuildbot arm-generic-full` now dies
TEST=`./cbuildbot/run_tests` passes

Change-Id: I381b16159b32018b8c6e03109d21a7d2d922b7c1
Reviewed-on: https://chromium-review.googlesource.com/202275
Reviewed-by: David James <davidjames@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cbuildbot.py b/scripts/cbuildbot.py
index 0631346..b2aaa8c 100644
--- a/scripts/cbuildbot.py
+++ b/scripts/cbuildbot.py
@@ -19,7 +19,6 @@
 import multiprocessing
 import pickle
 import sys
-import time
 import traceback
 
 from chromite.cbuildbot import cbuildbot_config
@@ -1624,14 +1623,7 @@
 
   elif (not options.buildbot and not options.remote_trybot
         and not options.resume and not options.local):
-    options.local = True
-    cros_build_lib.Warning(
-        'Running in LOCAL TRYBOT mode!  Use --remote to submit REMOTE '
-        'tryjobs.  Use --local to suppress this message.')
-    cros_build_lib.Warning(
-        'In the future, --local will be required to run the local '
-        'trybot.')
-    time.sleep(5)
+    cros_build_lib.Die('Please use --remote or --local to run trybots')
 
   # Only one config arg is allowed in this mode, which was confirmed earlier.
   bot_id = args[-1]