tst_QHostInfo: re-enable back the test on macOS

It went unnoticed (by me) the test was disabled via *.pro and later CMakeLists.txt
rather than BLACKLIST I was checking back then.

Fixes: QTBUG-129349
Change-Id: I509485bac9f32d544ef4bec120590a00d85ed608
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit e498a07)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

tests/auto/network/kernel/CMakeLists.txt

@@ -17,7 +17,7 @@ if(QT_FEATURE_udpsocket)
     add_subdirectory(qnetworkdatagram)
 endif()
 add_subdirectory(qhostaddress)
-if(QT_FEATURE_private_tests AND NOT MACOS AND NOT INTEGRITY)
+if(QT_FEATURE_private_tests AND NOT INTEGRITY)
     add_subdirectory(qhostinfo)
 endif()
 if(QT_FEATURE_private_tests)