fix blank last name

tournaments/models/player_registration.py

@@ -5,8 +5,8 @@ import uuid
 class PlayerRegistration(models.Model):
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=True)
     team_registration = models.ForeignKey(TeamRegistration, on_delete=models.CASCADE)
-    first_name = models.CharField(max_length=50)
+    first_name = models.CharField(max_length=50, blank=True)
-    last_name = models.CharField(max_length=50)
+    last_name = models.CharField(max_length=50, blank=True)
     licence_id = models.CharField(max_length=20, null=True, blank=True)
     rank = models.IntegerField(null=True, blank=True)
     #has_paid = models.BooleanField(default=False)