Fixing zombie conflicts (some vertices were wrongly detected alive)

Dependencies

• [2] 6YMDOZIB Refactoring apply
• [3] YN63NUZO Sanakirja 1.0
• [4] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).

Change contents

• replacement in libpijul/src/find_alive.rs at line 87
  [2.16310]→[3.767378:767403](∅→∅),[3.767378]→[3.767378:767403](∅→∅)
  − } else {
  [2.16310]

  [3.767403]
  + } else if v.flag().is_block() || vertex.is_empty() {