Fix gyp path for bwe simulator include.

TBR=pbos@webrtc.org

BUG=4479

Review URL: https://webrtc-codereview.appspot.com/49559004

Cr-Commit-Position: refs/heads/master@{#8887}
diff --git a/webrtc/modules/modules.gyp b/webrtc/modules/modules.gyp
index 4442d1c..c004d5a 100644
--- a/webrtc/modules/modules.gyp
+++ b/webrtc/modules/modules.gyp
@@ -234,7 +234,7 @@
             'remote_bitrate_estimator/test/packet_receiver.h',
             'remote_bitrate_estimator/test/packet_sender.cc',
             'remote_bitrate_estimator/test/packet_sender.h',
-            'remote_bitrate_estimator/test/packets.h',
+            'remote_bitrate_estimator/test/packet.h',
             'remote_bitrate_estimator/test/estimators/nada.cc',
             'remote_bitrate_estimator/test/estimators/nada.h',
             'remote_bitrate_estimator/test/estimators/remb.cc',