RFR: 8251188: Update LDAP tests not to use wildcard addresses [v2]

[Aleksei Efimov]

> Hi,
> 
> Please help to review [JDK-8251188](https://bugs.openjdk.java.net/browse/JDK-8251188) fix which helps to improve LDAP
> tests stability. The list of changes: 1. Usages of wildcard address have been replaced with loopback address. This
> change includes addition of `LDAPTestUtils.initEnv` method that takes LDAP provider URL as a parameter. 2.
> `DeadServerTimeoutSSLTest.java` was also updated to fix the intermittent failures reported by [JDK-8152654
> ](https://bugs.openjdk.java.net/browse/JDK-8152654) and
> [JDK-8169942](https://bugs.openjdk.java.net/browse/JDK-8169942). Before the fix the failure rate was 1 out of 4 runs.
> After the fix it was executed 400+ times alongside to other LDAP tests, and showed no failures, and therefore removed
> from the problem list.  Thank you, Aleksei

Aleksei Efimov has updated the pull request incrementally with one additional commit since the last revision:

  Update DeadServerTimeoutSSLTest to track and analyze client connections

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/252/files
  - new: https://git.openjdk.java.net/jdk/pull/252/files/606c24a8..81fe70b6

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=252&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=252&range=00-01

  Stats: 152 lines in 2 files changed: 140 ins; 1 del; 11 mod
  Patch: https://git.openjdk.java.net/jdk/pull/252.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/252/head:pull/252

PR: https://git.openjdk.java.net/jdk/pull/252