[FIX] account_asset_management: fix asset report

The Financial Assets report generates an error message where there is an asset
without depreciation table.
This is ok for most assets but not for those with method_number = 0 which
is the case for assets of type 'Land and Buildings'.

account_asset_management/report/account_asset_report_xls.py

@@ -494,7 +494,7 @@ def _has_assets(group, group_val):
                 lambda r: r.type == "depreciate"
             )
             dls_all = dls_all.sorted(key=lambda r: r.line_date)
-            if not dls_all:
+            if not dls_all and asset.method_number:
                 error_dict["no_table"] += asset
             # period_start_value
             dls = dls_all.filtered(lambda r: r.line_date <= wiz.date_from)