doc: fix a typo in 5.10.1's changelog

PR-URL: #6076
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Roman Klauke <romaaan.git@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

CHANGELOG.md

@@ -5,7 +5,7 @@
 ### Notable changes
 
 **http**:
-  * Enclose IPv6 Host header in square brackets. This will enable proper seperation of the host adress from any port reference (Mihai Potra) [#5314](https://github.com/nodejs/node/pull/5314)
+  * Enclose IPv6 Host header in square brackets. This will enable proper separation of the host adress from any port reference (Mihai Potra) [#5314](https://github.com/nodejs/node/pull/5314)
 
 **path**:
   * Make win32.isAbsolute more consistent (Brian White) [#6028](https://github.com/nodejs/node/pull/6028)