Added incompatible locale test to test/mhl/test-rfc6532.  It's a placeholder to show that 8-bit header field values aren't properly handled if the locale is incompatible.
Added incompatible locale test to test/mhl/test-rfc6532.  It's
a placeholder to show that 8-bit header field values aren't
properly handled if the locale is incompatible.

(cherry picked from commit 2cfa2ea56602d3bb0465a46c0b144017b497b558)

mcr/nmh,mcr/nmh