Fix the use of rowcount because it can return -1 or None according to PEP249

fiscalyear.py

@@ -91,7 +91,7 @@ class FiscalYear(ModelSQL, ModelView):
                         fiscalyear.end_date, fiscalyear.end_date,
                         fiscalyear.start_date, fiscalyear.end_date,
                         fiscalyear.company.id, fiscalyear.id))
-            if cursor.rowcount:
+            if cursor.fetchone():
                 return False
         return True
 

party.py

@@ -165,8 +165,6 @@ class Party(ModelSQL, ModelView):
                     'AND'.join(['(SUM((COALESCE(l.debit, 0) - COALESCE(l.credit, 0))) ' \
                         + ' ' + x[1] + ' %s) ' for x in args]),
                     [code] + today_value + [company_id] + [x[2] for x in args])
-        if not cursor.rowcount:
-            return [('id', '=', 0)]
         return [('id', 'in', [x[0] for x in cursor.fetchall()])]
 
 Party()

period.py

@@ -85,7 +85,7 @@ class Period(ModelSQL, ModelView):
                         period.end_date, period.end_date,
                         period.start_date, period.end_date,
                         period.fiscalyear.id, period.id))
-            if cursor.rowcount:
+            if cursor.fetchone():
                 return False
         return True