[python] Fix two memory leaks

[Tom Tromey]

>>>>> "Phil" == Phil Muldoon <pmuldoon@redhat.com> writes:

Phil> The unicode_decref patch changes the:
Phil> "python-utils.c/python_string_to_unicode" function to always return a
Phil> new reference.

Could you submit this to gdb-patches?  This utility code is already
there, so the fix needs to be as well.  Thanks.

Phil> The second patch is a straightforward addition of a variable
Phil> dereference inside the function:
Phil> "python.c/apply_val_pretty_printer". This value object was never being
Phil> dereferenced.

This is ok, thanks.

Tom