We need to catch index error here as well

Signed-off-by: Michal Čihař <michal@cihar.com>

weblate/trans/models/translation.py

@@ -1129,7 +1129,7 @@ class Translation(models.Model, URLMixin, PercentMixin, LoggerMixin):
             # Grab database unit
             try:
                 dbunit = self.unit_set.filter(checksum=checksum)[0]
-            except Unit.DoesNotExist:
+            except (Unit.DoesNotExist, IndexError):
                 continue
 
             # Indicate something new

weblate/trans/views/source.py

@@ -39,7 +39,7 @@ def get_source(request, project, subproject):
     obj = get_subproject(request, project, subproject)
     try:
         return obj, obj.translation_set.all()[0]
-    except Translation.DoesNotExist:
+    except (Translation.DoesNotExist, IndexError):
         raise Http404('No translation exists in this component.')