Add printStackTrace to approved scripts

Change-Id: I35f45c8515270e8190e531b59934bf2c2643274e
diff --git a/jenkins/client/approved_scripts.yml b/jenkins/client/approved_scripts.yml
index d947687..d65fecd 100644
--- a/jenkins/client/approved_scripts.yml
+++ b/jenkins/client/approved_scripts.yml
@@ -94,3 +94,4 @@
         - method java.util.regex.Matcher find
         - method hudson.model.Run getId
         - method java.util.regex.MatchResult groupCount
+        - method java.lang.Throwable printStackTrace