Remove misplaced pipe from reference output

tests/test_cli/test_show_windows_/test_requirements_3_6_.tree

@@ -1457,6 +1457,6 @@ repo_helper==2020.12.18
         ├── prettyprinter>=0.18.0
         │   ├── Pygments>=2.2.0
         │   └── colorful>=0.4.0
-        │   │   └── colorama; platform_system == "Windows"
+        │       └── colorama; platform_system == "Windows"
         ├── typing-extensions>=3.7.4.3
         └── yapf>=0.30.0