Welcome to Beta screen: Msg fix

Author: Stefterv

build/shared/lib/languages/PDE.properties

@@ -618,7 +618,7 @@ update_check.updates_available.contributions = There are updates available for s
 # Beta
 beta.window.title = Welcome to Beta
 beta.title = Welcome to the Processing Beta
-beta.message = Thank you for trying out the new version of Processing. We?re very grateful!\n\nPlease report any bugs on the forums.
+beta.message = Thank you for trying out the new version of Processing. We're very grateful!\n\nPlease report any bugs on the forums.
 beta.button = Got it!
 
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