tst_QAbstractNetworkCache autotest is unstable and crashes on exit sometimes.
On my workstation, while running it in an infinite loop, it crashed on exit after the 12th execution.
It also crashes in CI. A test log including a full backtrace is available at http://pulse.test.qt.nokia.com:8080/file/artifacts/126621007/_artifacts/test-logs/tst_qabstractnetworkcache-00.txt
|For Gerrit Dashboard: QTBUG-20686|
|2479,1||test: mark tst_qabstractnetworkcache as insignificant||master||qt/qtbase||Status: MERGED||+2||0|
|23152,1||re-enable qabstractnetworkcache autotest||master||qt/qtbase||Status: MERGED||+2||0|