fix url quotes in setup.cfg metadata

Author: RonnyPfannschmidt

setup.cfg

@@ -3,7 +3,7 @@
 name = pytest
 description = pytest: simple powerful testing with Python
 long_description = file: README.rst
-url = "https://docs.pytest.org/en/latest/"
+url = https://docs.pytest.org/en/latest/
 project_urls =
     Source=https://github.com/pytest-dev/pytest
     Tracker=https://github.com/pytest-dev/pytest/issues