LinkedFuture and SimpleDiskAndNetwork Tests fail on buildtype=release

Both fail only in release builds in the Future destructor.

--- command ---
16:42:45 MALLOC_PERTURB_='1' EMPER_STACKTRACE_ON_ABORTS='true' /home/fischerling/code/emper/build-release/tests/LinkFutureTest
--- stderr ---
    1742.698396097       EMPER_STACKTRACE_ON_ABORTS set to 'true': Enabling stacktrace on abort

Error: close Future 0x7fcba0080de0 created but never awaited
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20/22 EMPER:io / SimpleDiskAndNetworkTest                  FAIL           0.32s (killed by signal 11 SIGSEGV)

--- command ---
16:42:48 MALLOC_PERTURB_='1' EMPER_STACKTRACE_ON_ABORTS='true' /home/fischerling/code/emper/build-release/tests/SimpleDiskAndNetworkTest
--- stderr ---
    1742.858450978       EMPER_STACKTRACE_ON_ABORTS set to 'true': Enabling stacktrace on abort

Error: accept Future 0x7f7d4c010ec0 created but never awaited
-------