Click the ‘Run’ button under the instructions. It should complete, then have you change the message.
I ran into a number of issues with the Git course and felt at many different points the instructions could have been a little clearer. But at the same time, I probably should have slowed down and read more carefully and consider what the terminal was showing me. Once you get past this, you will likely have more similar oddities. Take your time the rest of the way.