Update Groovy version to resolve CVE-2020-17521

Author: bobbywarner

gradle.properties

@@ -4,7 +4,7 @@ commonsIOVersion=2.2
 springBootVersion=1.5.22.RELEASE
 springVersion=4.3.25.RELEASE
 spockVersion=1.1-groovy-2.4
-groovyVersion=2.4.17
+groovyVersion=2.4.21
 gradleSdkVendorVersion=1.1.1
 jaxbVersion=2.3.1
 javaxAnnotationApiVersion=1.3.2
@@ -35,4 +35,4 @@ servletApiVersion=3.0.1
 asyncVersion=3.3.2
 gspVersion=3.3.2
 legacyConvertersVersion=3.3.1
-testingSupportVersion=1.1.5
+testingSupportVersion=1.1.5