[damned-lies] Don't crash if doc format cannot be determined in update_stats

[Claude Paroz <claudep src gnome org>]

commit 0a4266d3c3825a20821337585056f2f4f118ce87
Author: Claude Paroz <claude 2xlibre net>
Date:   Tue Jun 26 09:21:31 2018 +0200

    Don't crash if doc format cannot be determined in update_stats

 stats/models.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/stats/models.py b/stats/models.py
index 0e81e377..277b2794 100644
--- a/stats/models.py
+++ b/stats/models.py
@@ -1597,7 +1597,11 @@ class Statistics(models.Model):
         stats = utils.po_file_stats(file_path)
         for err in stats['errors']:
             self.set_error(*err)
-        fig_stats = utils.get_fig_stats(file_path, self.domain.doc_format(self.branch))
+        try:
+            df = self.domain.doc_format(self.branch)
+        except Exception:
+            df = None
+        fig_stats = utils.get_fig_stats(file_path, df)
 
         if not self.full_po:
             self.full_po = PoFile.objects.create(path=file_path)