Revert H7 dijet samples to 7.1.6 tune, which will be used for these JOs

The aim of these JOs is to compare the Lund string model hadronisation to the cluster model. Herwig7 dijet samples with the cluster model exist here and are generated with version 7.1.6.

Therefore the new JOs for dijet with the Lund string model should also be generated with 7.1.6, to make a fair comparison of the two hadronisation models.