Fix linter issues

Author: mielvds

lib/pyld/jsonld.py

@@ -4346,7 +4346,7 @@ def _cleanup_preserve(self, input_, options):
                         idx = options['link'][id_].index(input_)
                         # already visited
                         return options['link'][id_][idx]
-                    except:
+                    except ValueError:
                         # prevent circular visitation
                         options['link'][id_].append(input_)
                 else:
@@ -4386,7 +4386,7 @@ def _cleanup_null(self, input_, options):
                         idx = options['link'][id_].index(input_)
                         # already visited
                         return options['link'][id_][idx]
-                    except:
+                    except ValueError:
                         # prevent circular visitation
                         options['link'][id_].append(input_)
                 else:
@@ -5019,7 +5019,8 @@ def _create_term_definition(self, active_ctx, local_ctx, term, defined, options,
                 mapping['@id'] = active_ctx['@vocab'] + term
 
         if (value.get('@protected') or
-            (defined.get('@protected') and value.get('@protected') != False)):
+            (defined.get('@protected') and value.get('@protected', True))):
+            warnings.warn(value.get('@protected'))
             mapping['protected'] = True
 
         if '@type' in value: