fixing input git username

Author: kbrashears5

entrypoint.sh

@@ -25,7 +25,7 @@ PULL_REQUEST_BRANCH_NAME="$INPUT_PULL_REQUEST_BRANCH_NAME"
 echo "Pull request    : $PULL_REQUEST_BRANCH_NAME"
 GIT_EMAIL="$INPUT_GIT_EMAIL"
 echo "Git email       : $GIT_EMAIL"
-GIT_USERNAME="$GIT_USERNAME"
+GIT_USERNAME="$INPUT_GIT_USERNAME"
 echo "Git username    : $GIT_USERNAME"
 
 # set temp path