Fix bug when triggering peak in an event is not from the salting peaks

[dachengx]

Following #73

In some very rare cases, the events will overlap with multiple salting peaks. So the triggering peak in an event might not be from the salting peaks but from other salting peaks. In these cases, the salting peaks are not triggering events, but theirs1_salting_number or s2_salting_number can be not -1, but we need to remove them from the definition of "triggering".

[coveralls]

Pull Request Test Coverage Report for Build 9060912996

Details

• 2 of 4 (50.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 50.401%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
axidence/plugins/cuts/cuts_event_building.py	2	4	50.0%

Totals
Change from base Build 9056332051:	0.0%
Covered Lines:	692
Relevant Lines:	1373

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💛 - Coveralls