Relax the threshold for datarate test by 5%

Change-Id: Ibc770df77939a68f9f0d1d78c0edd737b0d398ad
diff --git a/test/datarate_test.cc b/test/datarate_test.cc
index e8604a6..2b4aa3a 100644
--- a/test/datarate_test.cc
+++ b/test/datarate_test.cc
@@ -145,7 +145,7 @@
     cfg_.rc_target_bitrate = i;
     ResetModel();
     ASSERT_NO_FATAL_FAILURE(RunLoop(&video));
-    ASSERT_GE(cfg_.rc_target_bitrate, effective_datarate_)
+    ASSERT_GE(cfg_.rc_target_bitrate, effective_datarate_ * 0.95)
         << " The datarate for the file exceeds the target!";
 
     ASSERT_LE(cfg_.rc_target_bitrate, file_datarate_ * 1.3)