RFR: 8378927: H3MultipleConnectionsToSameHost.java#with-continuations intermittent fails

[Daniel Jeliński]

Raise the QUIC connection timeout in the H3MultipleConnectionsToSameHost test above the jtreg timeout.

The test failed with a QUIC connection timeout, but the reason for the timeout was not found in the logs. This kind of failure is usually caused by one of:
- packet loss; when that happens, the congestion controller slows down the sending rate until the connection times out,
- threading issues like races / deadlocks
- overloaded machine; the threads might not get enough CPU time to respond before the timeout expires.

Increasing the QUIC connection timeout should mitigate the packet loss and CPU issues, and will provide additional information like thread / core dumps to help with diagnosing threading issues.

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Commit messages:
 - Raise QUIC connection timeout above jtreg timeout

Changes: https://git.openjdk.org/jdk/pull/29993/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29993&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8378927
  Stats: 13 lines in 1 file changed: 6 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/29993.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29993/head:pull/29993

PR: https://git.openjdk.org/jdk/pull/29993