fixed incorrect 1-4 energies with OpenMP + energy groups

fixed incorrect 1-4 energies with OpenMP + energy groups

The OpenMP bonded thread data structure allocated too few energy group
elements with more than 1 energy group. This would lead to incorrect
1-4 interaction energies when atoms beyond the first energy group
were involved in 1-4 interactions (but sampling itself was correct).
Potentially this could also lead to memory corruption.
All this could only happen with more than 1 OpenMP thread.

Change-Id: Ib6b91862eaaddaafc0c609961219e01c7be0f9eb