Revert "upgrade to Groovy 1.8.9"

This reverts commit e4013a7.

Author: graemerocher

build.gradle

@@ -27,7 +27,7 @@ ext {
     datastoreVersion = "1.1.4.BUILD-SNAPSHOT"
     gantVersion = "1.9.6"
     gdocEngineVersion = "1.0.1"
-    groovyVersion = "1.8.9"
+    groovyVersion = "1.8.8"
     gradleGroovyVersion = groovyVersion
     gradleGroovyVersion = "1.8.2"
     ivyVersion = "2.2.0"

grails-bootstrap/src/main/groovy/org/codehaus/groovy/grails/resolve/GrailsCoreDependencies.java

@@ -167,7 +167,7 @@ public Object doCall() {
 
                         // dependencies needed at compile time
                         ModuleRevisionId[] groovyDependencies = {
-                            ModuleRevisionId.newInstance("org.codehaus.groovy", "groovy-all", "1.8.9")
+                            ModuleRevisionId.newInstance("org.codehaus.groovy", "groovy-all", "1.8.8")
                         };
                         registerDependencies(dependencyManager, compileTimeDependenciesMethod, groovyDependencies, "jline");