Update to Groovy 2.4.19

Fixes gh-8263

gradle/javaprojects.gradle

@@ -17,7 +17,7 @@ ext.commonsCollectionsVersion = '3.2.2'
 ext.commonsLoggingVersion = '1.2'
 ext.ehcacheVersion = '2.10.6'
 ext.gebVersion = '0.10.0'
-ext.groovyVersion = '2.4.4'
+ext.groovyVersion = '2.4.19'
 ext.hsqlVersion = '2.3.6'
 ext.hibernateVersion = '5.0.12.Final'
 ext.hibernateValidatorVersion = '5.3.6.Final'