Fix a broken unit test

This CL fixes a broken unit test that was introduced by
I0dbd47ef3ab737b1be8bd2c4707dbf1a8f5b57cf.

Change-Id: I719143d5ab020ebb9d20df04969c477f0138e972
diff --git a/src/test/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractorTest.java b/src/test/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractorTest.java
index d2a7480..33e8aa6 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractorTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractorTest.java
@@ -181,6 +181,7 @@
             .putAll(changeProperties)
             .putAll(accountProperties)
             .putAll(patchSetProperties)
+            .put("reason", "testReason")
             .put("ref", "refs/heads/testBranch")
             .build();