Reproduce with should include -Dtests.iters=N [LUCENE-6194]

I was playing with the patch on #7128, and hit a test failure, but then the "Reproduce with: " failed to reproduce, which threw me for a bit of a loop, until I realized it was missing the -Dtests.iters=N.

To see this, apply the patch on #7128 to trunk and then run this:

```
ant test -Dtestcase=TestPriorityQueue -Dtests.method=testRemovalsAndInsertions* -Dtests.seed=2576D26D551748E5 -Dtests.slow=true -Dtests.linedocsfile=/lucenedata/hudson.enwiki.random.lines.txt -Dtests.locale=ru_RU -Dtests.timezone=Europe/Paris -Dtests.asserts=true -Dtests.file.encoding=UTF-8 -Dtests.iters=10
```

(or just insert a random test failure into e.g. TestDemo or something).

It should fail, but the "Reproduce with: ..." line does not include -Dtests.iters=10. I think it should?

---
Migrated from [LUCENE-6194](https://issues.apache.org/jira/browse/LUCENE-6194) by Michael McCandless (@mikemccand), updated Jan 23 2015

Start by applying the patch from issue #7128 to trunk and running the provided `ant test` command for `TestPriorityQueue`, including `-Dtests.iters=10`. Inspect how the “Reproduce with:” command is assembled after the test failure, and verify that the generated command preserves the iteration setting and reproduces the failure.

Written by the indexing model from the issue text.