Removed outdated Dutch translation

Author: Stefterv

build/shared/lib/languages/PDE.properties

@@ -613,14 +613,6 @@ update_check = Update
 update_check.updates_available.core = A new version of Processing is available,\nwould you like to visit the Processing download page?
 update_check.updates_available.contributions = There are updates available for some of the installed contributions,\nwould you like to open the the Contribution Manager now?
 
-
-# ---------------------------------------
-# Beta
-beta.window.title = Welcome to Beta
-beta.title = Thanks for testing this Processing Beta!
-beta.message = This preview release lets us gather feedback and fix issues before the final version. **Some features may not work as expected.** If you encounter problems, [please post on the forum](https://discourse.processing.org) or [open a GitHub issue](https://github.com/processing/processing4/issues).
-beta.button = Ok
-
 # ---------------------------------------
 # Color Chooser