Update import statement of the multiblock coreCIF

[vaitkus]

Due to a recent renaming of the multiblock coreCIF dictionary, the import statement should be changed from:

    _import.get
        [{'dupl':Ignore  'file':multi_block_core.dic  'mode':Full
          'save':multiblock_core}]

to

    _import.get
        [
          {
           'dupl':Ignore  'file':cif_core_multiblock.dic  'mode':Full
           'save':CIF_CORE_MULTIBLOCK_HEAD
          }
        ]

Since the DDLm version of the imgCIF dictionary is produced using automated conversion, the underlying software should be updated as well.

[jamesrhester]

The underlying software does not hardcode the import statement so there is no issue. It is sufficient to update the command to execute the software as #28 has done.

[vaitkus]

Thank you for clarifying and sorry for the noise!