package/brltty: disable emacs and lua bindings

Disable lua bindings to avoid the following build failure if host-lua
and lua are built before brltty raised since bump to version 6.5 in
commit 82c6e87d5eaaf5b32aa340ab384f88539238cbe1 and
https://github.com/brltty/brltty/commit/42bf48ca010d9163652cb0a014662fa243132736:

configure: lua package: lua
configure: lua includes:
configure: lua libs: -L/home/autobuild/autobuild/instance-0/output-1/host/bin/../sparc64-buildroot-linux-gnu/sysroot/usr/lib -llua -lm -ldl
checking for lua5.4... no
checking for lua... /home/autobuild/autobuild/instance-0/output-1/host/bin/lua
configure: Lua shell: /home/autobuild/autobuild/instance-0/output-1/host/bin/lua
configure: Lua library directory: /home/autobuild/autobuild/instance-0/output-1/host/lib/lua/5.3

[...]

/usr/bin/install -c -d /home/autobuild/autobuild/instance-0/output-1/target/home/autobuild/autobuild/instance-0/output-1/host/lib/lua/5.3
/usr/bin/install -c -s --strip-program /bin/true brlapi.so /home/autobuild/autobuild/instance-0/output-1/target/home/autobuild/autobuild/instance-0/output-1/host/lib/lua/5.3
make[3]: Leaving directory '/home/autobuild/autobuild/instance-0/output-1/build/brltty-6.6/Bindings/Lua'

[...]

brltty: installs files in /home/autobuild/autobuild/instance-0/output-1/target//home/autobuild/autobuild/instance-0/output-1

While at it, disable emacs bindings which have also been added in
version 6.5 with
https://github.com/brltty/brltty/commit/64a487e29941df54796645229a872ecbe2a06bfe

Fixes:
 - http://autobuild.buildroot.org/results/f424e6727bbe61ea4b7703e93aae6fcab7506898
 - http://autobuild.buildroot.org/results/bf4a161fc66fb99a24f08bea3436b13738f2e383

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 19f06441e8b616159d45a552beac6e1fe05bc42a)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/brltty/brltty.mk

@@ -23,8 +23,10 @@ BRLTTY_CONF_ENV = \
 	PKG_CONFIG_FOR_BUILD=$(HOST_DIR)/bin/pkgconf
 
 BRLTTY_CONF_OPTS = \
+	--disable-emacs-bindings \
 	--disable-java-bindings \
 	--disable-lisp-bindings \
+	--disable-lua-bindings \
 	--disable-ocaml-bindings \
 	--disable-python-bindings \
 	--disable-tcl-bindings \