Use `Priority: optional` and reorder some fields

`Priority: extra` is deprecated
https://www.debian.org/doc/debian-policy/ch-archive.html#s-priorities

Change-Id: I2cfa0432240452a8fdd5e0b4a2fb8b4c908db612
diff --git a/ndncert/debian/control b/ndncert/debian/control
index 0485ef5..74ab264 100644
--- a/ndncert/debian/control
+++ b/ndncert/debian/control
@@ -1,28 +1,28 @@
 Source: ndncert
-Priority: extra
+Section: net
+Priority: optional
 Maintainer: Zhiyi Zhang <zhiyi@cs.ucla.edu>
 Build-Depends: debhelper (>= 8.0.0),
  python3 (>= 3.6.0),
  pkg-config (>= 0.26),
  libndn-cxx-dev (>= 0.6.5)
 Standards-Version: 3.9.2
-Section: net
-Homepage: http://github.com/named-data/ndncert
-Vcs-Git: git://github.com/named-data/ndncert
-Vcs-Browser: http://github.com/named-data/ndncert
+Homepage: https://github.com/named-data/ndncert
+Vcs-Browser: https://github.com/named-data/ndncert
+Vcs-Git: https://github.com/named-data/ndncert.git
 
 Package: libndncert
-Section: libs
 Architecture: i386 amd64 arm64 armel armhf ppc64el
+Section: libs
 Depends: ${shlibs:Depends}, ${misc:Depends}
 Description: NDN Certificate Management System
  The library to support NDNCERT protocol and help
  NDN entities to manage certificates.
 
 Package: libndncert-dev
+Architecture: i386 amd64 arm64 armel armhf ppc64el
 Section: libdevel
 Depends: libndncert (= ${binary:Version}), ${misc:Depends}, libndn-cxx-dev
-Architecture: i386 amd64 arm64 armel armhf ppc64el
 Description: NDN Certificate Management System
  The library to support NDNCERT protocol and help
  NDN entities to manage certificates.
@@ -30,16 +30,14 @@
  This package contains the development files (headers and libraries)
 
 Package: libndncert-dbg
-Section: debug
 Architecture: i386 amd64 arm64 armel armhf ppc64el
-Priority: extra
+Section: debug
 Depends: libndncert (= ${binary:Version}), ${misc:Depends}
-Multi-Arch: foreign
-Description: NDN Certificate Management System
+Description: NDN Certificate Management System (debugging symbols)
  The library to support NDNCERT protocol and help
  NDN entities to manage certificates.
  .
- This package contains the debugging symbols for the libraries.
+ This package contains the debugging symbols for the library.
 
 Package: ndncert
 Architecture: i386 amd64 arm64 armel armhf ppc64el
@@ -49,8 +47,8 @@
  NDN entities do certificate management.
 
 Package: ndncert-server
-Depends: ${shlibs:Depends}, ${misc:Depends}, ndncert, libndn-cxx, ndnsec, nfd
 Architecture: i386 amd64 arm64 armel armhf ppc64el
+Depends: ${shlibs:Depends}, ${misc:Depends}, ndncert, libndn-cxx, ndnsec, nfd
 Description: NDN Certificate Management System
  Daemon to support NDNCERT protocol and help
  NDN entities do certificate management.