Make the reboot required text more visible in the console output

The "A reboot is required to continue. Please reboot your system."
message is printed before the reports summary and thus is easily
overlooked by users.

This patch adds a second such message after the report summary to
improve this.

Jira: RHEL-22736

commands/upgrade/__init__.py

@@ -113,6 +113,11 @@ def upgrade(args, breadcrumbs):
 
     if workflow.failure:
         sys.exit(1)
+    elif not args.resume:
+        sys.stdout.write(
+            'Reboot the system to continue with the upgrade.'
+            ' This might take a while depending on the system configuration.\n'
+        )
 
 
 def register(base_command):