Describe the bug
Opens a new window for each capture although the following parameters are set:

• use tabs
• single instance of Ksnip
  

Expected behavior
Used to open a new tab in the existing instance

Screenshots
For 2 captures, opens 2 windows, the first with 1 tab, the second with 2 tabs:

Desktop (please complete the following information):

• OS: Ubuntu 20.04.3 LTS
• ksnip version : Continuous a657a8e
• Installed at the moment from https://github.com/ksnip/ksnip/releases/download/continuous/ksnip-1.10.0-continuous.deb