Update the rpm package signing to work with newer rpm version

Newer versions of rpmsign (rpm 4.13+), no longer prompt for the pass
phrase, but instead provide gpg with access to stdin/out to request it.

Because this process is deferred, you will also often end up with
warning output from rpmbuild before the prompt, so we can no longer
assume the prompt will be the first output.

This issue was discovered while trying to build rpm packages for
OpenSUSE 15 which has the newer rpm.

Signed-off-by: DJ Mountney <david@twkie.net>

resources/rpm/signing.erb

@@ -11,25 +11,14 @@ require 'pty'
 
 puts rpm_cmd
 PTY.spawn(rpm_cmd) do |r, w, pid|
-  prompt = r.read(19)
-
-  # match the expected prompt exactly, since that's the only way we know if
-  # something went wrong.
-  unless prompt == 'Enter pass phrase: '
-    STDERR.puts "unexpected output from `#{rpm_cmd}`: '#{prompt}'"
-    Process.kill(:KILL, pid)
-    exit 1
-  end
-
-  STDOUT.puts prompt
-  w.write("#{password}\n")
-
   # Keep printing output unti the command exits
   loop do
     begin
       line = r.gets
       puts line
-      if (line =~ /failed/) && !(line =~ /warning:/)
+      if line =~ /Enter pass phrase:/ || line =~ /Please enter the passphrase to unlock the OpenPGP secret key:/
+        w.write("#{password}\n")
+      elsif (line =~ /failed/) && !(line =~ /warning:/)
         STDERR.puts 'RPM signing failure'
         exit 1
       end