[source] umdns: update to latest git HEAD

[LEDE Commits]

blogic pushed a commit to source.git, branch master:
https://git.lede-project.org/25302c0a0871aaad7f5637c8d2715877125b16e7

commit 25302c0a0871aaad7f5637c8d2715877125b16e7
Author: John Crispin <john at phrozen.org>
AuthorDate: Tue Jan 2 12:58:05 2018 +0100

    umdns: update to latest git HEAD
    
    7897441 umdnsd: Replace strerror(errno) with %m.
    
    Signed-off-by: John Crispin <john at phrozen.org>
---
 package/network/services/umdns/Makefile | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/package/network/services/umdns/Makefile b/package/network/services/umdns/Makefile
index 5188ac5..7fae197 100644
--- a/package/network/services/umdns/Makefile
+++ b/package/network/services/umdns/Makefile
@@ -12,9 +12,9 @@ PKG_RELEASE:=1
 
 PKG_SOURCE_URL=$(LEDE_GIT)/project/mdnsd.git
 PKG_SOURCE_PROTO:=git
-PKG_SOURCE_DATE:=2017-09-28
-PKG_SOURCE_VERSION:=b84fdacb6e9f8f9d4b588db0ef191eba9bd99af9
-PKG_MIRROR_HASH:=e2f64d307a64eb12bcfb21077312850e672dd02a6ad7b3b139909a5dfaa1e906
+PKG_SOURCE_DATE:=2018-01-02
+PKG_SOURCE_VERSION:=78974417e182a3de8f78b7d73366ec0c98396b6c
+PKG_MIRROR_HASH:=a60f9eb9428ac3256cd7c3c6d4207c116cedf4d212b82e2f86c1bf7c7898fcbb
 
 PKG_MAINTAINER:=John Crispin <john at phrozen.org>
 PKG_LICENSE:=LGPL-2.1