Remove 1.9 info from the PR template

Author: zacharysarah

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,11 +1,5 @@
-> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-> For 1.9 Features: set Milestone to `1.9` and Base Branch to `release-1.9`
-> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-> NOTE: Please check the “Allow edits from maintainers” box (see image below) to
-> [allow reviewers to fix problems](https://help.github.com/articles/allowing-changes-to-a-pull-request-branch-created-from-a-fork/) on your patch and speed up the review process.
+> NOTE: After opening the PR, please *un-check and re-check* the ["Allow edits from maintainers"](https://help.github.com/articles/allowing-changes-to-a-pull-request-branch-created-from-a-fork/) box so that maintainers can work on your patch and speed up the review process. This is a temporary workaround to address a known issue with GitHub.> 
 >
 > Please delete this note before submitting the pull request.
->
-> NOTE: After opening the PR, please *un-check and re-check* the "Allow edits from maintainers" box. This is a temporary workaround to address a known issue with GitHub.
 
 ![Allow edits from maintainers checkbox](https://help.github.com/assets/images/help/pull_requests/allow-maintainers-to-make-edits-sidebar-checkbox.png)