category-ru: add nplus1.ru (#3674)

popular science magazine

data/category-ru

@@ -78,6 +78,7 @@ kinescopecdn.net   # Kinescope video hosting CDN
 litres.ru          # E-book and audiobook service
 meteoinfo.ru       # Hydrometeorological Center of Russia
 ngenix.net         # NGENIX is a Russian provider of acceleration and security services for public web resources
+nplus1.ru          # N+1, popular science magazine
 ognihome.com       # OGNI HOME resident portal
 pochta.ru          # Russian post
 ponyexpress.ru     # Courier delivery service