Fix order of saving transactions

Snapshot value was not calculated correctly

nummi/main/models.py

@@ -212,8 +212,8 @@ class Transaction(CustomModel):
 
     def save(self, *args, **kwargs):
         self.account = self.snapshot.account
-        self.snapshot.update_sum()
         super().save(*args, **kwargs)
+        self.snapshot.update_sum()
 
     def __str__(self):
         return f"{self.date} – {self.name}"