dropbear: allow build without dbclient

This can save ~16KBytes size for the ipk

Signed-off-by: Rosy Song <rosysong@rosinson.com>

package/network/services/dropbear/Config.in

@@ -73,4 +73,8 @@ config DROPBEAR_PUTUTLINE
 	help
 		Dropbear will use pututline() to write the utmp structure into the utmp file.
 
+config DROPBEAR_DBCLIENT
+	bool "Build dropbear with dbclient"
+	default y
+
 endmenu

package/network/services/dropbear/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=dropbear
 PKG_VERSION:=2019.78
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2
 PKG_SOURCE_URL:= \
@@ -28,7 +28,8 @@ PKG_FIXUP:=autoreconf
 PKG_CONFIG_DEPENDS:= \
 	CONFIG_TARGET_INIT_PATH CONFIG_DROPBEAR_ECC CONFIG_DROPBEAR_ECC_FULL \
 	CONFIG_DROPBEAR_CURVE25519 CONFIG_DROPBEAR_ZLIB \
-	CONFIG_DROPBEAR_UTMP CONFIG_DROPBEAR_PUTUTLINE
+	CONFIG_DROPBEAR_UTMP CONFIG_DROPBEAR_PUTUTLINE \
+	CONFIG_DROPBEAR_DBCLIENT
 
 include $(INCLUDE_DIR)/package.mk
 
@@ -132,7 +133,7 @@ endef
 define Build/Compile
 	+$(MAKE) $(PKG_JOBS) -C $(PKG_BUILD_DIR) \
 		$(TARGET_CONFIGURE_OPTS) \
-		PROGRAMS="dropbear dbclient dropbearkey scp" \
+		PROGRAMS="dropbear $(if $(CONFIG_DROPBEAR_DBCLIENT),dbclient,) dropbearkey scp" \
 		MULTI=1 SCPPROGRESS=1
 	+$(MAKE) $(PKG_JOBS) -C $(PKG_BUILD_DIR) \
 		$(TARGET_CONFIGURE_OPTS) \
@@ -143,7 +144,7 @@ define Package/dropbear/install
 	$(INSTALL_DIR) $(1)/usr/sbin
 	$(INSTALL_BIN) $(PKG_BUILD_DIR)/dropbearmulti $(1)/usr/sbin/dropbear
 	$(INSTALL_DIR) $(1)/usr/bin
-	$(LN) ../sbin/dropbear $(1)/usr/bin/dbclient
+	$(if $(CONFIG_DROPBEAR_DBCLIENT),$(LN) ../sbin/dropbear $(1)/usr/bin/dbclient,)
 	$(LN) ../sbin/dropbear $(1)/usr/bin/dropbearkey
 	$(INSTALL_DIR) $(1)/etc/config
 	$(INSTALL_CONF) ./files/dropbear.config $(1)/etc/config/dropbear