Fix masterBranchName mentioned twice (#588)

Author: Henry-Hiles

README.md

@@ -120,7 +120,6 @@ Determine the behavior for none existing properties or array elements.
 | branch           | The updated YAML file will be committed to this branch, branch will be created if not exists                                                                                                                     | `master`                                              |
 | force            | Allows force pushes                                                                                                                                                                                              | `false`                                               |
 | masterBranchName | Branch name of your master branch                                                                                                                                                                                | `master`                                              |
-| masterBranchName | Branch name of your master branch                                                                                                                                                                                | `master`                                              |
 | githubAPI        | BaseURL for all GitHub REST API requests                                                                                                                                                                         | https://api.github.com                                |
 | token            | GitHub API Token which is used to create the PR, have to have right permissions for the selected repository                                                                                                      | ${{github.token}}                                     |
 | commitUserName   | Name used for the commit user                                                                                                                                                                                    | github-actions[bot]                                   |