sling-mock: Prevent StdOut logging from ESAPI

ESAPI: WARNING: System property [org.owasp.esapi.opsteam] is not set
ESAPI: WARNING: System property [org.owasp.esapi.devteam] is not set
ESAPI: Attempting to load ESAPI.properties via file I/O.
ESAPI: Attempting to load ESAPI.properties as resource file via file I/O.
ESAPI: Not found in 'org.owasp.esapi.resources' directory or file not readable: D:\Develop\github\wcm-io\io.wcm.samples\bundles\core\ESAPI.properties
ESAPI: Not found in SystemResource Directory/resourceDirectory: .esapi\ESAPI.properties
ESAPI: Not found in 'user.home' (C:\Users\stefan.seifert) directory: C:\Users\stefan.seifert\esapi\ESAPI.properties
ESAPI: Loading ESAPI.properties via file I/O failed. Exception was: java.io.FileNotFoundException
ESAPI: Attempting to load ESAPI.properties via the classpath.
ESAPI: SUCCESSFULLY LOADED ESAPI.properties via the CLASSPATH from '/ (root)' using current thread context class loader!
ESAPI: SecurityConfiguration for Validator.ConfigurationFile.MultiValued not found in ESAPI.properties. Using default: false
ESAPI: Attempting to load validation.properties via file I/O.
ESAPI: Attempting to load validation.properties as resource file via file I/O.
ESAPI: Not found in 'org.owasp.esapi.resources' directory or file not readable: D:\Develop\github\wcm-io\io.wcm.samples\bundles\core\validation.properties
ESAPI: Not found in SystemResource Directory/resourceDirectory: .esapi\validation.properties
ESAPI: Not found in 'user.home' (C:\Users\stefan.seifert) directory: C:\Users\stefan.seifert\esapi\validation.properties
ESAPI: Loading validation.properties via file I/O failed.
ESAPI: Attempting to load validation.properties via the classpath.
ESAPI: SUCCESSFULLY LOADED validation.properties via the CLASSPATH from '/ (root)' using current thread context class loader!