fix: Added an object checking
fix: Added an object checking

- Checking if there are objects in the event, and then
  if there is at least 1 transaction object
- This prevents the module from crashing, but does not
  guaranty having a valid GoAML file (depending on
  objects and their relations)

VirusTotal/misp-modules,VirusTotal/misp-modules,MISP/misp-modules,amuehlem/misp-modules,amuehlem/misp-modules,amuehlem/misp-modules,MISP/misp-modules,VirusTotal/misp-modules,MISP/misp-modules