bug: budget is lost when merging a category

[Kevin Decherf]

Homebank 5.1.6 / Linux Exherbo

Budget entries are lost for categories which are merged into another.

Steps to reproduce:

1. Create a category A
2. Set a budget for this category
3. Create a category B
4. Merge category A into B
5. Budget is not merged into B and is consequently lost

Expected behavior:

The budget of the former category should be merged into the target category.

[Maxime DOYEN (mdoyen)]

I don't agree.
When you merge A to B, you define that A will be substituted by B everywhere) and the drop A and so the budget of A.
Adding to this, the budget might be incompatible (same for each month vs different per month)