treewide: add conffiles

Signed-off-by: Huangbin Zhan <zhanhb88@gmail.com>

net/restic-rest-server/Makefile

@@ -2,7 +2,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=restic-rest-server
 PKG_VERSION:=0.9.7
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_BUILD_DIR:=$(BUILD_DIR)/rest-server-$(PKG_VERSION)
 PKG_SOURCE:=rest-server-$(PKG_VERSION).tar.gz
@@ -33,6 +33,10 @@ define Package/restic-rest-server
   CATEGORY:=Network
 endef
 
+define Package/restic-rest-server/conffiles
+/etc/config/restic-rest-server
+endef
+
 define Package/restic-rest-server/description
 Rest Server is a high performance HTTP server that implements restic's REST backend
 API. It provides secure and efficient way to backup data remotely, using restic

utils/device-observatory/Makefile

@@ -2,7 +2,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=device-observatory
 PKG_VERSION:=1.2.0
-PKG_RELEASE:=5
+PKG_RELEASE:=6
 
 PKG_SOURCE_URL:=https://codeload.github.com/mwarning/device-observatory/tar.gz/v$(PKG_VERSION)?
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
@@ -22,6 +22,10 @@ define Package/device-observatory
 	DEPENDS:=+iw +libpcap +libmicrohttpd
 endef
 
+define Package/device-observatory/conffiles
+/etc/config/device-observatory
+endef
+
 define Package/device-observatory/description
 	Show information about connected devices and connections to increase security awareness.
 endef

utils/prometheus-statsd-exporter/Makefile

@@ -2,7 +2,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=prometheus-statsd-exporter
 PKG_VERSION:=0.15.0
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=statsd_exporter-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://codeload.github.com/prometheus/statsd_exporter/tar.gz/v${PKG_VERSION}?
@@ -42,6 +42,7 @@ define Package/prometheus-statsd-exporter/install
 endef
 
 define Package/prometheus-statsd-exporter/conffiles
+/etc/config/prometheus-statsd-exporter
 /etc/prometheus-statsd-exporter.yml
 endef