Release 2.17 (#4836)

see https://github.com/kimai/kimai/pull/4836

src/Entity/Project.php

@@ -481,6 +481,7 @@ class Project implements EntityWithMetaFields, EntityWithBudget
             $this->addTeam($team);
         }
 
+        $this->number = null;
         $currentMeta = $this->meta;
         $this->meta = new ArrayCollection();
         /** @var ProjectMeta $meta */