don't fail on error in version templates json (#4346)

src/pfwbged/basecontent/browser/adddmsfile.py

@@ -55,7 +55,10 @@ def file_source(context):
     except AttributeError:
         version_templates = '/ foo'
     if os.path.exists(version_templates):
-        templates = json.load(file(version_templates))
+        try:
+            templates = json.load(file(version_templates))
+        except:
+            templates = []
         for entry in templates:
             if entry.get('portal_types') and context.portal_type not in entry.get('portal_types'):
                 continue