Merge pull request #874 from henklaak/fix_editsdefaults2 · python-control/python-control@08dcc95

Original file line number	Diff line number	Diff line change
`@@ -101,7 +101,8 @@ def editsdefaults():`
`101`	`101`	`"""Make sure any changes to the defaults only last during a test."""`
`102`	`102`	`restore = control.config.defaults.copy()`
`103`	`103`	`yield`
`104`		`-control.config.defaults = restore.copy()`
	`104`	`+control.config.defaults.clear()`
	`105`	`+control.config.defaults.update(restore)`
`105`	`106`
`106`	`107`
`107`	`108`	`@pytest.fixture(scope="function")`