Catch/display error when exporting QB invoices

don't let it raise to email alert

tailbone_quickbooks/views/quickbooks/invoices.py

@@ -411,7 +411,16 @@ class ExportableInvoiceView(MasterView):
             return self.redirect(self.get_index_url())
 
         # perform actual export and capture result
-        result = self.do_export(invoices)
+        try:
+            result = self.do_export(invoices)
+
+        except Exception as error:
+            log.warning("failed to export invoices: %s",
+                        [inv.uuid for inv in invoices],
+                        exc_info=True)
+            self.request.session.flash(simple_error(error), 'error')
+            return self.redirect(self.request.get_referrer(
+                default=self.get_index_url()))
 
         # clear out current checkbox selection
         self.set_selected(set())