JsonEnumMappingTest.TestData: Remove unused ctor

Change-Id: I08f221093c48c4d31a4752dc36e06d9ab7693f40
diff --git a/javatests/com/google/gerrit/json/JsonEnumMappingTest.java b/javatests/com/google/gerrit/json/JsonEnumMappingTest.java
index 6e57b01..dd710f9 100644
--- a/javatests/com/google/gerrit/json/JsonEnumMappingTest.java
+++ b/javatests/com/google/gerrit/json/JsonEnumMappingTest.java
@@ -71,10 +71,6 @@
 
   private static class TestData {
     TestEnum value;
-
-    public TestData(TestEnum value) {
-      this.value = value;
-    }
   }
 
   private enum TestEnum {