MPI_Type_free still called for bool

[ventrebd]

c5270b0 added an explicit MPI_Type_free for the MPI_Type_commit on bool.
When the bool type was converted to a built-in type (MPI_CXX_BOOL/MPI_C_BOOL), the explicit free was not removed.

My debugger found this with a __debugbreak() throw in Kernel32 in a debug build with MSMPI 10.1.3 and boost 1.91.0 when destructing boost::mpi::environment & calling mpi_datatype_map::clear.
Release builds seem to run ok, but that may be just because the program is already headed down and this is one of the last destructors to run.

[aminiussi]

It's been merged on develop. Since we're in beta 1 and it does not crash, is there a reason to push for a merge to master ?

[ventrebd]

I tried adding some more actions after the forced break, and my program was able to continue after smashing F5 a couple of times. I think the fix can wait until the next release of boost. Thanks!