Update to logback-classic:1.1.11

Fixes gh-5811

gradle/javaprojects.gradle

@@ -26,7 +26,7 @@ ext.javaPersistenceVersion = '2.1.1'
 ext.jettyVersion = '6.1.26'
 ext.jstlVersion = '1.2.1'
 ext.junitVersion = '4.12'
-ext.logbackVersion = '1.1.2'
+ext.logbackVersion = '1.1.11'
 ext.powerMockVersion = '1.6.2'
 ext.seleniumVersion = '2.44.0'
 ext.servletApiVersion = '3.1.0'