Merge pull request #15580 from lpichler/fix_chargeback_report_with_un…

…assigned_rates

Fix chargeback report with unassigned rates
(cherry picked from commit 03df095)

https://bugzilla.redhat.com/show_bug.cgi?id=1472837

app/models/miq_report/formatting.rb

@@ -69,7 +69,7 @@ def format(col, value, options = {})
     # Chargeback Reports: Add the selected currency in the assigned rate to options
     if Chargeback.db_is_chargeback?(db)
       @rates_cache ||= Chargeback::RatesCache.new
-      options[:unit] = @rates_cache.currency_for_report
+      options[:unit] = @rates_cache.currency_for_report if @rates_cache.currency_for_report
     end
 
     format.merge!(options) if format # Merge additional options that were passed in as overrides