Replace further deprecated calls to #deliver

See 868d764a.

Signed-off-by: Alex Coles <alex@alexbcoles.com>

app/workers/deliver_watcher_notification_job.rb

@@ -47,6 +47,6 @@ class DeliverWatcherNotificationJob
       UserMailer.work_package_watcher_added(watcher.watchable, watcher.user, watcher_setter)
     }
 
-    mail.deliver
+    mail.deliver_now
   end
 end

spec/workers/mail_notification_jobs/deliver_watcher_notification_job_spec.rb

@@ -45,8 +45,8 @@ describe DeliverWatcherNotificationJob, type: :model do
 
   before do
     # make sure no actual calls make it into the UserMailer
-    allow(UserMailer).to receive(:work_package_watcher_added).and_return(double('mail',
+    allow(UserMailer).to receive(:work_package_watcher_added)
-                                                                                deliver: nil))
+      .and_return(double('mail', deliver_now: nil))
   end
 
   it 'sends a mail' do
@@ -60,7 +60,7 @@ describe DeliverWatcherNotificationJob, type: :model do
     describe 'exceptions should be raised' do
       before do
         mail = double('mail')
-        allow(mail).to receive(:deliver).and_raise(SocketError)
+        allow(mail).to receive(:deliver_now).and_raise(SocketError)
         expect(UserMailer).to receive(:work_package_watcher_added).and_return(mail)
       end