Approve get method for hudson.EnvVars object

Change-Id: Idc9711d2de5b5878fa0b0cbd324436e581764c09
diff --git a/jenkins/client/approved_scripts.yml b/jenkins/client/approved_scripts.yml
index 80cfd95..8122e8c 100644
--- a/jenkins/client/approved_scripts.yml
+++ b/jenkins/client/approved_scripts.yml
@@ -15,6 +15,7 @@
         - method groovy.util.Node attributes
         - method groovy.util.XmlParser parse java.io.File
         - method groovy.util.XmlParser parseText java.lang.String
+        - method hudson.EnvVars get java.lang.String java.lang.String
         - method hudson.PluginManager getPlugins
         - method hudson.PluginWrapper getShortName
         - method hudson.model.Hudson getSlaves