update NEWS with a new fix

Signed-off-by: Howard Pritchard <howardp@lanl.gov>

NEWS

@@ -61,6 +61,8 @@ included in the vX.Y.Z section and be denoted as:
 ------------------------
 
 - Update embedded PMIx to 3.1.2.
+- Fix an issue with MPI_WIN_CREATE_DYNAMIC and MPI_GET from self.
+  thanks to Bart Janssens for reporting.
 - Fix an issue of excessive compiler warning messages from mpi.h
   when using newer C++ compilers.  Thanks to @Shadow-fax for
   reporting.