Fix typo in configuring rails guide. [ci-skip]
Fix typo in configuring rails guide. [ci-skip]

georgeclaghorn/rails,esparta/rails,esparta/rails,georgeclaghorn/rails,rails/rails,yahonda/rails,MSP-Greg/rails,georgeclaghorn/rails,rails/rails,yahonda/rails,yahonda/rails,esparta/rails,MSP-Greg/rails,georgeclaghorn/rails,MSP-Greg/rails,yahonda/rails,MSP-Greg/rails,esparta/rails,rails/rails,rails/rails