python-3.5: Fix manifest to handle reprlib correctly

The current line is looking for py files in __pycache__ which is incorrect.
Fix it to correctly include the right files (modelled after ${PN}-signal).

Patch isn't relavent to later releases since manifest generation changed
significantly.

[YOCTO #12831]

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>