Add an Open MPI-specific comment here so that we hopefully don't lose

this change the next time we update libevent.

cmr=v1.7.4:ticket=3882

This commit was SVN r29597.

The following Trac tickets were found above:
  Ticket 3882 --> https://svn.open-mpi.org/trac/ompi/ticket/3882

opal/mca/event/libevent2021/libevent/include/Makefile.am

@@ -38,6 +38,8 @@ EXTRA_SRC = $(EVENT2_EXPORT)
 ## the source header filename to derive the installed header filename.
 ## With nobase_ the installed path is $(includedir)/event2/ev*.h.
 
+# Open MPI: comment this out, because we don't want these header files
+# installed
 # if INSTALL_LIBEVENT
 # nobase_include_HEADERS =	$(EVENT2_EXPORT)
 # nobase_nodist_include_HEADERS = ./event2/event-config.h