If an issue is iterated several times in a template, the export should be counted once.

Currently, if 2 Test cases are linked to 6 Defects, the export count is 14 (2+6+6).
ie. iterations with linked issues affect the number of export issues. 

This suggestion is to improvise to minimize the export count. If an issue is iterated several times in a template, the export should be counted once.
example, 2 Tests linked to 6 Defects, the export count should be 8 (2+6)