Change "race" to "ethnic origin"

contributing/code_of_conduct/index.rst

@@ -8,7 +8,7 @@ In the interest of fostering an open and welcoming environment, we as
 contributors and maintainers pledge to making participation in our project and
 our community a harassment-free experience for everyone, regardless of age, body
 size, disability, ethnicity, gender identity and expression, level of experience,
-education, socio-economic status, nationality, personal appearance, race,
+education, socio-economic status, nationality, personal appearance, ethnic origin,
 religion, or sexual identity and orientation.
 
 Our Standards