How do I unblock a number that is not on the GO SMS Black List?

I accidentally blocked a number when GO SMS asked me if it was OK for GO SMS Emoji to send message. I pressed DON'T SEND and REMEMBER MY CHOICE, and now I can't find where to change that setting. The number does not appear on my BLACK LIST or WHITE LIST and I had to use the stock messenger on my phone to send to that number. Where do I change that setting so I can text to that number again with GO SMS?

Try going to Settings>Apps, select Go SMS, and Clear Defaults.