package/apache: add brotli as optional dependency

Fixes:
http://autobuild.buildroot.net/results/90e/90e3a2aaf0ce0451b80c71743209797abeb83d0a/
http://autobuild.buildroot.net/results/006/006f94bb216a77f073a5670fa2f393c43f15a977/
http://autobuild.buildroot.net/results/dd6/dd69e665e51ce6b30e303a4d4670e9edbb159aea/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/apache/apache.mk

@@ -45,6 +45,13 @@ APACHE_CONF_OPTS = \
 	--with-mpm=$(APACHE_MPM) \
 	--disable-luajit
 
+ifeq ($(BR2_PACKAGE_BROTLI),y)
+APACHE_CONF_OPTS += --enable-brotli
+APACHE_DEPENDENCIES += brotli
+else
+APACHE_CONF_OPTS += --disable-brotli
+endif
+
 ifeq ($(BR2_PACKAGE_LIBXML2),y)
 APACHE_DEPENDENCIES += libxml2
 # Apache wants the path to the header file, where it can find