[1p][mpfa][test] Fix input file

test/porousmediumflow/1p/implicit/test_mpfa1p.input

@@ -3,18 +3,15 @@ DtInitial = 1 # [s]
 TEnd = 1 # [s]
 
 [Grid]
-File = ./grids/test_1p_2d.dgf
+UpperRight = 1 1
+Cells = 10 10
 
 [Problem]
 Name = 1ptestmpfao # name passed to the output routines
 
 [SpatialParams]
-LensLowerLeftX = 0.2 # [m]
-LensLowerLeftY = 0.2 # [m]
-LensLowerLeftZ = 0.2 # [m]
-LensUpperRightX = 0.8 # [m]
-LensUpperRightY = 0.8 # [m]
-LensUpperRightZ = 0.8 # [m]
+LensLowerLeft = 0.2 0.2 # [m]
+LensUpperRight = 0.8 0.8 # [m]
 
 Permeability = 1e-10 # [m^2]
 PermeabilityLens = 1e-12 # [m^2]