Bug 362478 - Thunderbird win32 tinderbox shouldn't build with winver 0x400

r=rhelmer@mozilla.com (Robert Helmer)
sr=mscott@mozilla.com (Scott MacGregor)

tools/tinderbox-configs/thunderbird/win32/mozconfig

@@ -20,4 +20,3 @@ ac_add_options --enable-official-branding
 ac_add_options --disable-shared
 ac_add_options --enable-static
 ac_add_options --enable-update-packaging
-ac_add_options --with-windows-version=400