Exclude test utils class from tests

If not ignored ConfigSetupUtils is considered a test suite
and an initializationError is thrown because of the multiple
class constructors:

java.lang.IllegalArgumentException: Test class can only have one constructor

Change-Id: Ieae27e635ea1c3d0a3a884ef3240bacb6fcc8028
diff --git a/src/test/java/com/googlesource/gerrit/plugins/gitrepometrics/ConfigSetupUtils.java b/src/test/java/com/googlesource/gerrit/plugins/gitrepometrics/ConfigSetupUtils.java
index 2872ea9..2fa05d6 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/gitrepometrics/ConfigSetupUtils.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/gitrepometrics/ConfigSetupUtils.java
@@ -25,7 +25,9 @@
 import java.nio.file.Path;
 import java.util.List;
 import org.eclipse.jgit.lib.Config;
+import org.junit.Ignore;
 
+@Ignore
 public class ConfigSetupUtils {
   static final String pluginName = "git-repo-metrics";
   private final Path basePath;