fix: deferred report division by zero exception

erpnext/accounts/report/deferred_revenue_and_expense/deferred_revenue_and_expense.py

@@ -121,6 +121,7 @@ class Deferred_Item(object):
 		"""
 		simulate future posting by creating dummy gl entries. starts from the last posting date.
 		"""
+		if self.service_start_date != self.service_end_date:
 			if add_days(self.last_entry_date, 1) < self.period_list[-1].to_date:
 				self.estimate_for_period_list = get_period_list(
 					self.filters.from_fiscal_year,