remove no longer required line from README

Signed-off-by: Adam Warner <[email protected]>

Author: PromoFaux

README.md

@@ -219,5 +219,3 @@ You can add as many attachments of any type to a message as you want. Message me
 
 We welcome everyone who wants to contribute to this repo!
 Just open an issue with your intention or make a comment in some open issue you would like to work on.
-
-Please ensure that your Pull Requests are based on, and submitted against the development branch.