Remove incorrect alternative solution q19

The reshape-based solution for q19 did only work for odd numbered squares, not even ones such as 8x8 squares.

source/exercises100.ktx

@@ -211,12 +211,6 @@ Z[1::2,::2] = 1
 Z[::2,1::2] = 1
 print(Z)
 
-# Alternative solution: Using reshaping
-arr = np.ones(64,dtype=int)
-arr[::2]=0
-arr = arr.reshape((8,8))
-print(arr)
-
 < q20
 Consider a (6,7,8) shape array, what is the index (x,y,z) of the 100th element? (★☆☆)