autotest: Delete devserver_dir config

BUG=b:191304437
TEST=None

Change-Id: I2c3c08d46b87eb62895020e226fad513556809c6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/2998520
Commit-Queue: Allen Li <ayatane@chromium.org>
Tested-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Derek Beckett <dbeckett@chromium.org>
Reviewed-by: Congbin Guo <guocb@chromium.org>
diff --git a/global_config.ini b/global_config.ini
index 46e0056..cc303ba 100644
--- a/global_config.ini
+++ b/global_config.ini
@@ -304,10 +304,6 @@
 rpm_sentry_password: fake_password
 rpm_frontend_uri: http://chromeos-rpm-server.mtv.corp.google.com:9999
 
-# Path the devserver source tree, used for spawning devserver from autoserv in
-# some of the tests. Please override in local shadow config file.
-#devserver_dir: /path/to/src/platform/dev
-
 lab_status_url: http://chromiumos-lab.appspot.com/current?format=json
 
 sam_instances: cautotest