Set show_diff to false for Nova SSH private key

The private key is currently being leaked into
the diff output.

Change-Id: I94170f76257c77d1eabeeb3d373c05c50413c53d
(cherry picked from commit 75fbe61987)

manifests/init.pp

@@ -553,11 +553,12 @@ but should be one of: ssh-rsa, ssh-dsa, ssh-ecdsa, ssh-ed25519.")
       }
 
       file { $nova_private_key_file:
-        content => $nova_private_key[key],
-        mode    => '0600',
-        owner   => $::nova::params::user,
-        group   => $::nova::params::group,
-        require => File['/var/lib/nova/.ssh'],
+        content   => $nova_private_key[key],
+        mode      => '0600',
+        owner     => $::nova::params::user,
+        group     => $::nova::params::group,
+        show_diff => false,
+        require   => File['/var/lib/nova/.ssh'],
       }
     }
   }

spec/classes/nova_init_spec.rb

@@ -355,10 +355,11 @@ describe 'nova' do
 
         it 'should install ssh private key' do
           is_expected.to contain_file("/var/lib/nova/.ssh/#{keyname}").with(
-            :content => 'keydata',
-            :mode    => '0600',
-            :owner   => 'nova',
-            :group   => 'nova',
+            :content   => 'keydata',
+            :mode      => '0600',
+            :owner     => 'nova',
+            :group     => 'nova',
+            :show_diff => false,
           )
         end
       end
@@ -374,7 +375,7 @@ describe 'nova' do
       it 'should raise an error' do
         expect {
           is_expected.to contain_file('/var/lib/nova/.ssh/id_rsa').with(
-            :content => 'keydata'
+            :content => 'keydata',
           )
         }.to raise_error Puppet::Error, /You must provide both a key type and key data./
       end