[JENKINS-34751] use patched version of Groovy 2.4.6 (#2369)

contains fixes for GROOVY-7761 and GROOVY-7826

[FIXES JENKINS-34751]

core/pom.xml

@@ -41,7 +41,7 @@ THE SOFTWARE.
     <staplerFork>true</staplerFork>
     <stapler.version>1.243</stapler.version>
     <spring.version>2.5.6.SEC03</spring.version>
-    <groovy.version>2.4.6</groovy.version>
+    <groovy.version>2.4.6-jenkins-1</groovy.version>
   </properties>
 
   <dependencies>