Don't propose an empty list of changes to push

Dependencies

• [2] 5HF7C67M push/pull: fixed "changes" arguments
• [*] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).

Change contents

• edit in pijul/src/commands/pushpull.rs at line 190
  [4.116982]

  [2.372]
  +

  + if to_upload.is_empty() {

  + return Ok(());

  + }

  +