nfd: Update to version 0.6.6

Change-Id: Ic2097ec6da6fd561c2ab1c931834cd89d3d10636
diff --git a/nfd/debian/control b/nfd/debian/control
index f517352..268e702 100644
--- a/nfd/debian/control
+++ b/nfd/debian/control
@@ -5,7 +5,7 @@
  dh-systemd (>= 1.5),
  python (>= 2.7.0),
  pkg-config (>= 0.26),
- libndn-cxx-dev (>= 0.6.5),
+ libndn-cxx-dev (>= 0.6.6),
  python-sphinx,
  libpcap-dev (>= 1.5.3),
  libboost-all-dev (>= 1.58.0),