reference point - on processor boundary!

multiphase/interIsoFoam/sloshingTank2D

1. Please correct the decomposerParDict to (1 2 2) since 2D case.

2. With this correction, when solver is initiated, it fails with error

[3] --> FOAM FATAL IO ERROR: 
[3] Unable to set reference cell for field p
    Reference point pRefPoint (0 0 0.15) found on 2 domains (should be one)

@andy @Mattijs @mark @Sergio