Expect fail for MNG-947 with Maven 3.0.5

Due to the addition of MNG-6229 it turns out that Maven 3.0.5 resolves
optional dependencies differently than other versions. The oldest
version to pass this IT is 3.1.0-alpha-1.

its/core-it-suite/src/test/java/org/apache/maven/it/MavenITmng0947OptionalDependencyTest.java

@@ -46,6 +46,8 @@ public class MavenITmng0947OptionalDependencyTest
     public void testit()
         throws Exception
     {
+        failingMavenVersions( "(,3.1.0-alpha-1)" );
+
         File testDir = ResourceExtractor.simpleExtractResources( getClass(), "/mng-0947" );
 
         Verifier verifier = newVerifier( testDir.getAbsolutePath() );