RFR: 8347506: Compatible OCSP readtimeout property with OCSP timeout

[Jamil Nimeh]

This makes a small change to the default value of the `com.sun.security.ocsp.readtimeout` System property.  When not explicitly specified, it will be set to the value of the `com.sun.security.ocsp.timeout` System property, which helps ease the transition from older JDK versions where this property did not exist.

This change is already part of the [17u backport](https://github.com/openjdk/jdk17u-dev/pull/2747), we are just forward-porting the same change into newer versions.

Bug: https://bugs.openjdk.org/browse/JDK-8347506
CSR: https://bugs.openjdk.org/browse/JDK-8347749
Original fix: https://bugs.openjdk.org/browse/JDK-8179502 (for reference)

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

Commit messages:
 - 8347506: Compatible OCSP readtimeout property with OCSP timeout

Changes: https://git.openjdk.org/jdk/pull/23118/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23118&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8347506
  Stats: 73 lines in 2 files changed: 70 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/23118.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23118/head:pull/23118

PR: https://git.openjdk.org/jdk/pull/23118