Don't force a dependency on nfd

Other compatible forwarders may be used

Change-Id: I0736af1619e3b33ebb7c580928ad9b54f9854f04
diff --git a/nfd/debian/control b/nfd/debian/control
index 673c230..d7fded4 100644
--- a/nfd/debian/control
+++ b/nfd/debian/control
@@ -25,22 +25,25 @@
 
 Package: nfd-status-http-server
 Architecture: i386 amd64 arm64 armel armhf ppc64el
-Depends: nfd (= ${binary:Version}), ${misc:Depends}, python3 (>= 3.6.0)
+Depends: ${misc:Depends}, nfd, python3 (>= 3.6.0)
 Description: NFD HTTP status server
 
 Package: nfd-autoreg
 Architecture: i386 amd64 arm64 armel armhf ppc64el
-Depends: nfd (= ${binary:Version}), ${misc:Depends}
+Depends: ${shlibs:Depends}, ${misc:Depends}, ndnsec
+Suggests: nfd
 Description: NFD autoreg server
 
 Package: ndn-autoconfig-server
 Architecture: i386 amd64 arm64 armel armhf ppc64el
-Depends: nfd (= ${binary:Version}), ${misc:Depends}
+Depends: ${shlibs:Depends}, ${misc:Depends}, ndnsec
+Suggests: nfd
 Description: NDN autoconfig server
 
 Package: ndn-autoconfig-client
 Architecture: i386 amd64 arm64 armel armhf ppc64el
-Depends: nfd (= ${binary:Version}), ${misc:Depends}
+Depends: ${shlibs:Depends}, ${misc:Depends}
+Suggests: nfd
 Description: NDN autoconfig client
 
 Package: nfd-all