document fix testing_pylintrc now showing issue pylint-dev#5687

Author: orSolocate

doc/development_guide/testing.rst

@@ -12,6 +12,14 @@ Test your code!
 
 Pylint is very well tested and has a high code coverage. New contributions are not accepted
 unless they include tests.
+
+Before you start testing your code, you need to install your source-code package locally.
+The best way to do so is running this terminal command:
+
+ python setup.py develop
+
+This ensures your testing environment is similar to Pylint's testing environment on GitHub.
+
 Pylint uses two types of tests: unittests and functional tests.
 
   - The unittests can be found in the ``/pylint/test`` directory and they can

pylint/testutils/lint_module_test.py

@@ -47,12 +47,11 @@ def __init__(
         rc_file: Union[Path, str] = PYLINTRC
         try:
             rc_file = test_file.option_file
-        except NoFileError:
-            pass
-        finally:
             self._linter.disable("suppressed-message")
             self._linter.disable("locally-disabled")
             self._linter.disable("useless-suppression")
+        except NoFileError:
+            pass
 
         try:
             args = [test_file.source]