[source] opkg: re-enable usign support

[LEDE Commits]

jow pushed a commit to source.git, branch master:
https://git.lede-project.org/55ffc3800430befdde3c27078641afcb30e8b9b8

commit 55ffc3800430befdde3c27078641afcb30e8b9b8
Author: Jo-Philipp Wich <jo at mein.io>
AuthorDate: Mon Feb 20 15:03:33 2017 +0100

    opkg: re-enable usign support
    
    The switch to cmake caused the -DHAVE_USIGN flag to get lost, disabling
    compilation of the correspondinf support code.
    
    Update to latest Git head which enables usign support by default.
    
    Signed-off-by: Jo-Philipp Wich <jo at mein.io>
---
 package/system/opkg/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/package/system/opkg/Makefile b/package/system/opkg/Makefile
index 5586ead..44ced06 100644
--- a/package/system/opkg/Makefile
+++ b/package/system/opkg/Makefile
@@ -15,8 +15,8 @@ PKG_RELEASE:=1
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://git.lede-project.org/project/opkg-lede.git
-PKG_SOURCE_DATE:=2017-02-18
-PKG_SOURCE_VERSION:=db3fc0ce879bfe784d32ffe5a70e057459039dd5
+PKG_SOURCE_DATE:=2017-02-20
+PKG_SOURCE_VERSION:=bec9804c73acf74ba112c9eec4ce7ba97e140c89
 PKG_MIRROR_HASH:=
 
 PKG_LICENSE:=GPL-2.0