net-tools: remove libintl static linking handling

net-tools: remove libintl static linking handling

We no longer support building the full-blown libintl in static linking
scenarios, as it causes too many problems. Patch
0001-Makefile-fix-static-linking-issue-with-lintl.patch was added to
allow passing -lintl through LIBS, in a place that works for static
linking.

However, for dynamic linking, we can simply pass -lintl through the
existing LDFLAGS variable, as it was done prior to commit
38bfd129c64a9cfd82c4fa4c797afadf12a6ffaa ("package/net-tools: fix
static linking issue with lintl").

This commit does that and gets rid of the now useless patch.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>