[BUG] Manager stops on error when starting a filter

[frikilax]

Describe the bug
Manager stops Darwin when one filter fails to start.
Occures basically when the executable given is not found (OS error)

Plateform (please complete the following information):

• OS (version): every OS
• Darwin version: all actual versions

To Reproduce
Steps to reproduce the behavior:

1. Make a darwin.conf with several valid filters, but one with wrong executable path
2. Follow darwin_manager.log
3. Try to start the Darwin service
4. See error when starting the filter with wrong path, and manager stop on error (also stopping all succesfully started filters)

Expected behavior
Manager should fail on startup for this filter, but continue for next ones and only generate error in logs.
Other filters should be started normally.

[frikilax]

Solved in Hotfix #115