package/libnftnl: drop obsolete patch

Patch #1 is obsolete since upstream commit 244d60de2f1 ("utils: define
xfree() as macro") in version 1.0.3. xfree is no longer a symbol, so it
can't conflict with symbols of the code libnftnl links with.

Cc: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>