[widgets][algorithmeditor] Make resistant to "empty" JSON

Empty as in "{}"

beat/editor/widgets/algorithmeditor.py

@@ -283,7 +283,7 @@ class PropertyEditor(QWidget):
     def load(self, json_object):
         self.schema_version = json_object.get("schema_version")
         self.api_version = json_object.get("api_version")
-        self.language = json_object["language"]
+        self.language = json_object.get("language")
         self.analyzer_checkbox.setChecked("results" in json_object)
         algorithm_type = json_object.get("type", "legacy")
         for button in self.button_group.buttons():