package/gettext-tiny: do not install headers

package/gettext-tiny: do not install headers

Since:

    https://github.com/sabotage-linux/gettext-tiny/commit/58187329ad9f00eb8c39379e7ee0b608dd14bab8

gettext macrosesss are used by default (if no LIBINTL_NO_MACROS is
included in CPPFLAGS). It causes packages such as libglib2 to fail
building with argument format errors because in case of error the
formatted string is passed as argument.

Fix it by prevent the installation of libintl.h header from
gettext-tiny by passing LIBINTL=NONE, because each kind of toolchain
already provides gettext stubs. Also with this change the following
patch is not needed:

	0001-libintl-Fix-format-not-a-string-literal-error-for-gc.patch

Fixes:
	http://autobuild.buildroot.net/results/89fcc4e80ea8c031c1abb350362c19c57eb80e7c/
	http://autobuild.buildroot.net/results/84f3eb70fc1c58986dfa7c79d45aaabdf4c011cf/

and a lot other autobuild reports.

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>