package/apache: fix lua detection

Patch suggested by Thomas: Adding a path to --with-lua disables
pkgconf-based detection of lua, which in some cases needs libdl.

This patch removes --with-lua which fixes
http://autobuild.buildroot.net/results/cc1/cc13f4cef9cf6f18615d58f1d83b233812f19fa0/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/apache/apache.mk

@@ -57,9 +57,7 @@ APACHE_CONF_OPTS += \
 endif
 
 ifeq ($(BR2_PACKAGE_LUA),y)
-APACHE_CONF_OPTS += \
-	--enable-lua \
-	--with-lua=$(STAGING_DIR)/usr
+APACHE_CONF_OPTS += --enable-lua
 APACHE_DEPENDENCIES += lua
 else
 APACHE_CONF_OPTS += --disable-lua