Remove errornous file from MANIFEST

There has never really existed a file called
python-ethtool/etherinfo_ipv6_obj.h

Signed-off-by: David Sommerseth <davids@redhat.com>

Author: David Sommerseth

MANIFEST

@@ -9,7 +9,6 @@ python-ethtool/etherinfo_ipv6_obj.c
 python-ethtool/etherinfo_struct.h
 python-ethtool/etherinfo.h
 python-ethtool/etherinfo_obj.h
-python-ethtool/etherinfo_ipv6_obj.h
 setup.py
 rpm/SPECS/python-ethtool.spec
 MANIFEST