warning fix in the bmon unpacker

This MR fixes the following compiler warning:

/home/cbmdock/cbmroot/algo/detectors/bmon/Unpack.cxx: In member function 'cbm::algo::bmon::Unpack::resultType cbm::algo::bmon::Unpack::operator()(const uint8_t*, const fles::MicrosliceDescriptor&, uint64_t) const':
/home/cbmdock/cbmroot/algo/detectors/bmon/Unpack.cxx:130:50: warning: '*((void*)& time +8)' may be used uninitialized in this function [-Wmaybe-uninitialized]
     double messageTime  = message.getMsgFullTimeD(time.currentEpochInTs) - elinkPar.fTimeOffset;
                           ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
/home/cbmdock/cbmroot/algo/detectors/bmon/Unpack.cxx:27:14: note: '*((void*)& time +8)' was declared here
     TimeSpec time;
              ^~~~

The compiler complains that time.currentEpochInTs field may be used uninitialized. In fact, the code logic is correct because there is a check that ensures the first message is an epoch message. But it is too complicated for the compiler. I rewrote the code to read the first message explicitly as an epoch message. It makes the compiler happy.

requested review from @d.smith

assigned to @d.smith

changed the description

Dear @f.uhlig, @v.friese, @p.-a.loizeau,

you have been identified as code owner of at least one file which was changed with this merge request.

Please check the changes and approve them or request changes.

added CodeOwners label

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Looks ok.

approved this merge request

added 51 commits

• 2bd4776b...68f68cfe - 50 commits from branch computing:master
• 8419a3fe - warning fix in the bmon unpacker

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enabled an automatic merge when the pipeline for 8419a3fe succeeds

merged

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