Fix CA/CRL refresh retriggering every run on 304

When the server responds with 304 Not Modified, ca_last_update and
crl_last_update were not updated. Since these read the mtime of the
CA cert / CRL file on disk, the stale timestamp caused needs_refresh?
to return true on every subsequent run, ignoring ca_refresh_interval
and crl_refresh_interval.

Fix by updating the timestamp on 304 so the interval is respected.

Author: houssemexo26

lib/puppet/ssl/state_machine.rb

@@ -121,6 +121,7 @@ def refresh_ca(ssl_ctx, last_update)
     rescue Puppet::HTTP::ResponseError => e
       if e.response.code == 304
         Puppet.info(_("CA certificate is unmodified, using existing CA certificate"))
+        @cert_provider.ca_last_update = Time.now
       else
         Puppet.info(_("Failed to refresh CA certificate, using existing CA certificate: %{message}") % { message: e.message })
       end
@@ -219,6 +220,7 @@ def refresh_crl(ssl_ctx, last_update)
     rescue Puppet::HTTP::ResponseError => e
       if e.response.code == 304
         Puppet.info(_("CRL is unmodified, using existing CRL"))
+        @cert_provider.crl_last_update = Time.now
       else
         Puppet.info(_("Failed to refresh CRL, using existing CRL: %{message}") % { message: e.message })
       end