Swap row and column variable names
Swap row and column variable names

The column and row indicies were incorrectly named. While purely
aesthetic, the program logic and output is now consistent with the
README descriptions.

JDSWalker/n-Queens_Problem,JDSWalker/n-Queens_Problem,JDSWalker/n-Queens_Problem,JDSWalker/n-Queens_Problem,JDSWalker/n-Queens_Problem