Add changes entry about R attribute fix

CHANGES.current

@@ -7,6 +7,15 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.0.2 (in progress)
 ===========================
 
+2020-01-30: richardbeare
+            #1511 [R] Fix bug wrapping functions. These were previously incorrectly wrapped as if
+            they were variables. This happened when 'get' or 'set' was in the name of the function
+            or method, but sometimes also in some other circumstances. If you were using R
+            attribute syntax to access these methods, you'll need to switch to calling them as R
+            methods.
+
+            *** POTENTIAL INCOMPATIBILITY ***
+
 2020-01-24: etse-dignitas, wsfulton
             #1533 [C#, D, Java] Fix upcasting for shared_ptr's of templated types.