Fixed Import in boundaries_in_kernel

lbmpy/boundaries/boundaries_in_kernel.py

 import sympy as sp
 
-from lbmpy.boundaries.boundaryhandling import BoundaryOffsetInfo, LbmWeightInfo
+from lbmpy.boundaries.boundaryhandling import LbmWeightInfo
+from pystencils.boundaries.boundaryhandling import BoundaryOffsetInfo
 from pystencils.assignment import Assignment
 from pystencils.astnodes import Block, Conditional, LoopOverCoordinate, SympyAssignment
 from pystencils.data_types import type_all_numbers