djeuscan: pkg.metadata can fail

Signed-off-by: Corentin Chary <corentin.chary@gmail.com>

euscanwww/djeuscan/processing/scan/scan_metadata.py

@@ -49,8 +49,14 @@ class ScanMetadata(object):
         if created:
             self.logger.info('+ [p] %s/%s' % (pkg.category, pkg.name))
 
+        try:
             if not pkg.metadata:
                 return
+        except Exception as e:
+            self.logger.error(
+                self.style.ERROR('%s/%s: %s' % (pkg.category, pkg.name, str(e)))
+            )
+            return
 
         herds = dict(
             [(herd[0], herd) for herd in pkg.metadata.herds(True)]