Fixes JENKINS-23274: remove log of script content

Avoids the script content appearing in the build output. Script execution is logged, but not the content of script.

src/main/java/org/jenkinsci/plugins/envinject/service/EnvInjectEnvVars.java

@@ -121,7 +121,7 @@ public int executeScript(boolean loadFromMaster,
             return new HashMap<String, String>();
         }
 
-        logger.info(String.format("Evaluation the following Groovy script content: %n%s%n", scriptContent));
+        logger.info("Evaluating the Groovy script content");
 
         Binding binding = new Binding();
         String jobName = envVars.get("JOB_NAME");