dropbear: let opkg manage symlinks of ssh, scp

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

package/network/services/dropbear/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=dropbear
 PKG_VERSION:=2017.75
-PKG_RELEASE:=5
+PKG_RELEASE:=6
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2
 PKG_SOURCE_URL:= \
@@ -49,6 +49,10 @@ define Package/dropbear
   CATEGORY:=Base system
   TITLE:=Small SSH2 client/server
   DEPENDS:= +DROPBEAR_ZLIB:zlib
+  ALTERNATIVES:=\
+	  100:/usr/bin/ssh:/usr/sbin/dropbear \
+	  100:/usr/bin/scp:/usr/sbin/dropbear \
+
 endef
 
 define Package/dropbear/description
@@ -131,8 +135,6 @@ 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/scp
-	$(LN) ../sbin/dropbear $(1)/usr/bin/ssh
 	$(LN) ../sbin/dropbear $(1)/usr/bin/dbclient
 	$(LN) ../sbin/dropbear $(1)/usr/bin/dropbearkey
 	$(INSTALL_DIR) $(1)/etc/config