fix: processing error because all directive rules pointed to the same first_event and flag

[mmta]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 96.55172% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 95.39%. Comparing base (9316c25) to head (2c7c3e5).
Report is 4 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #75      +/-   ##
==========================================
- Coverage   95.48%   95.39%   -0.09%     
==========================================
  Files          33       33              
  Lines        5070     5145      +75     
==========================================
+ Hits         4841     4908      +67     
- Misses        229      237       +8     

Flag	Coverage Δ
unittests	95.39% <96.55%> (-0.09%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
server/src/backlog/mod.rs	96.20% <100.00%> (-0.51%)	⬇️
server/src/rule.rs	97.93% <100.00%> (+0.32%)	⬆️
server/src/backlog/manager.rs	82.77% <85.71%> (-2.86%)	⬇️

... and 2 files with indirect coverage changes