Disable gettext tests that require threads

gettext fails to build with a toolchain with no threads support just
because some gettext tests (that aren't used in Buildroot) require
threads. We therefore disable the build of such tests.

Since the change in Makefile.in is simple, we also make it in this
patch, which avoids the need to autoreconf the gettext package.

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

Index: b/gettext-tools/Makefile.am
===================================================================
--- a/gettext-tools/Makefile.am
+++ b/gettext-tools/Makefile.am
@@ -20,7 +20,7 @@
 AUTOMAKE_OPTIONS = 1.5 gnu no-dependencies
 ACLOCAL_AMFLAGS = -I m4 -I ../gettext-runtime/m4 -I ../autoconf-lib-link/m4 -I ../m4 -I gnulib-m4 -I libgettextpo/gnulib-m4
 
-SUBDIRS = doc intl gnulib-lib libgrep libuniname src libgettextpo po projects misc man m4 tests examples
+SUBDIRS = doc intl gnulib-lib libgrep libuniname src libgettextpo po projects misc man m4 examples
 
 EXTRA_DIST = misc/DISCLAIM
 MOSTLYCLEANFILES = core *.stackdump
Index: b/gettext-tools/Makefile.in
===================================================================
--- a/gettext-tools/Makefile.in
+++ b/gettext-tools/Makefile.in
@@ -484,7 +484,7 @@
 top_srcdir = @top_srcdir@
 AUTOMAKE_OPTIONS = 1.5 gnu no-dependencies
 ACLOCAL_AMFLAGS = -I m4 -I ../gettext-runtime/m4 -I ../autoconf-lib-link/m4 -I ../m4 -I gnulib-m4 -I libgettextpo/gnulib-m4
-SUBDIRS = doc intl gnulib-lib libgrep libuniname src libgettextpo po projects misc man m4 tests examples
+SUBDIRS = doc intl gnulib-lib libgrep libuniname src libgettextpo po projects misc man m4 examples
 
 # Allow users to use "gnulib-tool --update".