Fixes an issue reported by Robert G. (gan@mercon24.de) on user ML. I created <<Error in PartyFinancialHistory.groovy calculation of the "totalToBeReceived" / "totalToBePayed" >> https://issues.apache.org/jira/browse/OFBIZ-5339 for that

I previously refactored PartyFinancialHistory.groovy at r1528144, r1528146, r1528149, r1528298

git-svn-id: https://svn.apache.org/repos/asf/ofbiz/trunk@1529418 13f79535-47bb-0310-9956-ffa450edef68