Fix test coverage of options class

tests/test_core/test_core_options.py

@@ -42,6 +42,7 @@ def testCoreOptions_LoadSave(monkeypatch, mockGUI, fncPath):
     # Write a test file
     optFile = metaDir / nwFiles.OPTS_FILE
     optFile.write_text(json.dumps({
+        "novelWriter.guiOptions": {
             "GuiProjectSettings": {
                 "winWidth": 570,
                 "winHeight": 375,
@@ -52,6 +53,7 @@ def testCoreOptions_LoadSave(monkeypatch, mockGUI, fncPath):
             "MockGroup": {
                 "mockItem": None,
             },
+        },
     }), encoding="utf-8")
 
     # Load and save with no path set