bpo-36811: Fix a C compiler warning in _elementtree.c. (GH-13109)

bpo-36811: Fix a C compiler warning in _elementtree.c. (GH-13109) · python/cpython@6b95149

Original file line number	Diff line number	Diff line change
`@@ -1171,7 +1171,7 @@ checkpath(PyObject* tag)`
`1171`	`1171`	`char *p = PyBytes_AS_STRING(tag);`
`1172`	`1172`	`const Py_ssize_t len = PyBytes_GET_SIZE(tag);`
`1173`	`1173`	`if (len >= 3 && p[0] == '{' && (`
`1174`		`-p[1] == '}' \|\| p[1] == '*' && p[2] == '}')) {`
	`1174`	`+p[1] == '}' \|\| (p[1] == '*' && p[2] == '}'))) {`
`1175`	`1175`	`/* wildcard: '{}tag' or '{}tag' /`
`1176`	`1176`	`return 1;`
`1177`	`1177`	`}`