bpo-21536: Update What's New in Python 3.8 entry (GH-13242)

Android still links to libpython.

Author: vstinner

Doc/whatsnew/3.8.rst

@@ -138,7 +138,8 @@ environment variable, can be set using the new ``./configure --with-trace-refs``
 build option.
 (Contributed by Victor Stinner in :issue:`36465`.)
 
-On Unix, C extensions are no longer linked to libpython. It is now possible
+On Unix, C extensions are no longer linked to libpython except on Android.
+It is now possible
 for a statically linked Python to load a C extension built using a shared
 library Python.
 (Contributed by Victor Stinner in :issue:`21536`.)