typo in date (dashpay#1241)

Author: schinzelh

contrib/gitian-descriptors/gitian-rpi2.yml

@@ -15,7 +15,7 @@ packages:
 - "faketime"
 - "bsdmainutils"
 - "binutils-gold"
-reference_datetime: "2017-01-10 00:00:00"
+reference_datetime: "2017-01-01 00:00:00"
 remotes:
 - "url": "https://github.com/dashpay/dash.git"
   "dir": "dash"