Add runtime dependency on ed

Use of 'patch --ed' requires ed. For those unfamiliar with this
functionality (like me), here is a reproducer:
$ echo foo > a
$ cp a b
$ echo bar >> b
$ diff --ed a b > patch
$ patch --ed a patch
patch: /usr/bin/ed subprocess failed: No such file or directory
patch: **** /usr/bin/ed FAILED

I ran into this issue when running 'quilt annotate'.

patch.spec

@@ -39,6 +39,8 @@ BuildRequires: libattr-devel
 BuildRequires: ed
 BuildRequires: autoconf automake
 
+Requires: ed
+
 Provides: bundled(gnulib) = %{gnulib_ver}
 
 %description