Updated Xen 4.19 schedule

["Oleksii K." <oleksii.kurochko@xxxxxxxxx>]

Hello everyone,

I would like to announce that I have decided to update the Xen 4.19
schedule due to the extended feature freeze period and the upcoming Xen
Summit next week.

I propose the following updates:
   Code Freeze: from May 31 to June 7
   Hard Code Freeze: from June 21 to June 28
   Final commits: from July 5 to July 12
   Release: July 17
The release date is shifted, but it still remains in July, which seems
acceptable to me.

One more thing:
No release ack is needed before Rc1. Please commit bug fixes at will.

Have a nice day.

Best regards,
Oleksii