i18n: Fix Russian language native name (#193)

data/i18n/languages.yaml

@@ -4,7 +4,7 @@
 "eu": "Euskara"
 "fr": "Français"
 "nl": "Nederlands"
-"ru": "русский язык"
+"ru": "Русский"
 "tr": "Türkçe"
 "vi": "Tiếng Việt"
 "zh": "中文 (简体)"