Update apprtc to 5eb702d341796.

This updates the import in collider.go, which I hope will solve the
runhooks problems for the WebRTC chromium bots.

BUG=581283
TBR=henrika@chromium.org

Review URL: https://codereview.chromium.org/1634803003 .
diff --git a/prebuilt_apprtc.zip.sha1 b/prebuilt_apprtc.zip.sha1
index 91fac5b..7e2833e 100644
--- a/prebuilt_apprtc.zip.sha1
+++ b/prebuilt_apprtc.zip.sha1
@@ -1 +1 @@
-8d4b34745722b9f8aa7849961cda4d937cf22763
\ No newline at end of file
+6a96fc234cfa92ffaa79b0aeb5f4bdc1f31c6340
\ No newline at end of file