Fix clang compilation error

The used structured bindings are only supported with C++20 and even then there
is a bug in clang with some older version which crash during compilation. The
fix doesn't capture the structured binding.

algo/unpack/Unpack.cxx

@@ -184,8 +184,17 @@ namespace cbm::algo
     std::vector<fles::MicrosliceDescriptor> msDesc;  // microslice descriptors
     std::vector<const u8*> msContent;                // pointer to microslice content
     auto legalEqIds = GetEqIds(algos);
-    auto [numMs, sizeBytes] =
+
+    //    Workaround a problem for some clang versions
+    //    Capturing structured bindings either is avaialable with C++20
+    //    Obviously GCC supports it already and has no problems but clang or at
+    //    least some clang versions fail during compilation
+    //    auto [numMs, sizeBytes] =
+    //      ParallelInit(ts, subsystem, gsl::make_span(legalEqIds), sys_ver, genericMonitor, msEqIds, msDesc, msContent);
+    std::pair<size_t, size_t> tmp =
       ParallelInit(ts, subsystem, gsl::make_span(legalEqIds), sys_ver, genericMonitor, msEqIds, msDesc, msContent);
+    auto numMs     = tmp.first;
+    auto sizeBytes = tmp.second;
     std::vector<std::vector<Digi>> msDigis(numMs);  // unpacked digis per microslice
     std::vector<Monitor> monitor(numMs);            // unpacking monitoring data per microslice