collectd: remove redundant liblua link flag

The link flag makes the main program depend on liblua in official
package feeds, even if collectd-mod-lua is not installed.
The plugin is already linked against liblua.so, so this can be removed.

Signed-off-by: Qingfang Deng <dqfext@gmail.com>
[added PKG_RELEASE bump]
(cherry picked from commit aa0a14e2dd)

utils/collectd/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=collectd
 PKG_VERSION:=5.12.0
-PKG_RELEASE:=54
+PKG_RELEASE:=55
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2
 PKG_SOURCE_URL:=https://collectd.org/files/ \
@@ -232,8 +232,7 @@ $(call Package/collectd/Default)
   DEPENDS:= +libpthread \
 	  +zlib \
 	  +libltdl \
-	  +jshn \
-	  +PACKAGE_collectd-mod-lua:liblua
+	  +jshn
   MENU:=1
 endef
 
@@ -272,11 +271,6 @@ CONFIGURE_VARS+= \
 	LDFLAGS="$$$$LDFLAGS -lm -lz" \
 	KERNEL_DIR="$(LINUX_DIR)"
 
-ifneq ($(CONFIG_PACKAGE_collectd-mod-lua),)
-CONFIGURE_VARS+= \
-	LDFLAGS="$$$$LDFLAGS -llua"
-endif
-
 ifneq ($(CONFIG_PACKAGE_COLLECTD_ENCRYPTED_NETWORK),)
 CONFIGURE_ARGS+= \
 	--with-libgcrypt=$(STAGING_DIR)/usr