Problem description: Low-level discovery creates duplicate triggers if two or more trigger prototypes generate identical triggers.

Steps to reproduce:

1. Import the following host:
   
2. Send the following value to the LLD rule:

   zabbix_server -z 127.0.0.1 -s test -k trap -o '\{"data":[\{"\{#M}":"5"}]}'
   

3. Open the list of triggers for host test and check the discovered triggers.

Result: Two completely identical triggers were created:

It is even possible to set both triggers into status problem and they will generate identical problems.
Expected: only one trigger should've been discovered, since LLD should prevent creation of duplicate triggers.