opkg: bump to version 2019-06-14

Opkg starting from this version special-cases busybox as alternatives
provider.  There should be no need to add entries to ALTERNATIVES of
busybox package

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

package/system/opkg/Makefile

@@ -14,9 +14,9 @@ PKG_FLAGS:=essential
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://git.openwrt.org/project/opkg-lede.git
-PKG_SOURCE_DATE:=2019-01-31
-PKG_SOURCE_VERSION:=d4ba162bb3f931bd5a019154270a548cf1f0853b
-PKG_MIRROR_HASH:=dc97e6f6409031422c3c52c513209a6b806b219713c2898cb32fb95d34e92008
+PKG_SOURCE_DATE:=2019-06-14
+PKG_SOURCE_VERSION:=dcbc142e51f5f5f2fb9e4e44657e013d3c36a52b
+PKG_MIRROR_HASH:=fca7e71dd06f0d5ee0af0d0a493d641d4d5d7e403d64c67879a462a020aa2299
 
 PKG_LICENSE:=GPL-2.0
 PKG_LICENSE_FILES:=COPYING