DeleteChangeUsingHAGerrit2: Fix json change number

Before this change, the (change) number field used by that scenario was
solely automatic. Make that value either set from a composing scenario,
such as CreateChangeUsingHAGerrit1, or through the existing 'number'
test environment property; cf. [1]. DeleteChangeUsingHAGerrit2 was
already able to be run standalone, so adjust that field accordingly.

[1] https://gerrit-documentation.storage.googleapis.com/Documentation/2.16.19/dev-e2e-tests.html#_environment_properties

Change-Id: Ife99acb3e8511814d63cf52d69748c0bfe9fb41d
diff --git a/src/test/resources/com/ericsson/gerrit/plugins/highavailability/scenarios/DeleteChangeUsingHAGerrit2.json b/src/test/resources/com/ericsson/gerrit/plugins/highavailability/scenarios/DeleteChangeUsingHAGerrit2.json
index 55167bd..8e0a304 100644
--- a/src/test/resources/com/ericsson/gerrit/plugins/highavailability/scenarios/DeleteChangeUsingHAGerrit2.json
+++ b/src/test/resources/com/ericsson/gerrit/plugins/highavailability/scenarios/DeleteChangeUsingHAGerrit2.json
@@ -1,6 +1,6 @@
 [
   {
     "url": "http://HOSTNAME:HTTP_PORT2/a/changes/",
-    "number": "_NUMBER"
+    "number": "NUMBER"
   }
 ]