Problem after editing payed invoice item quantity.

[metecwb]

items stock quantity is calculated wrong after editing a payed invoice item quantity.

Steps to reproduce the issue

check an items stock quantity. open a payed invoice and edit quantity of one item you checked .
say you have 100 more items in stock. and you changed item quantity of invoice from 1 to 2.

Expected result

after invoice is saved, items is expected to be 99

Actual result

but actually its 98.

System information (Akaunting, PHP versions)

Akaunting 1.3.3 and php 7.2.7

Additional comments

[cuneytsenturk]

thanks for reporting. @metecwb