RFR: 8049520: FileCredentialsCache loads cache once and is never refreshed [v2]

[Weijun Wang]

> Just re-load the CredentialsCache like we did on non-Windows non-macOS systems.

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  test info

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5960/files
  - new: https://git.openjdk.java.net/jdk/pull/5960/files/dbfd4f66..8cd6de4d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5960&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5960&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5960.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5960/head:pull/5960

PR: https://git.openjdk.java.net/jdk/pull/5960