doc: fix spelling error in sept 2020 sec post

Refs: #3385 (comment)

Author: MylesBorins

locale/en/blog/vulnerability/september-2020-security-releases.md

@@ -30,7 +30,7 @@ Impacts:
 
 Thank you to Paolo Insogna and Matteo Collina who work at NearFom for reporting and fixing this vulnerability.
 
-### fs.realpath.native on may cause buffer overflow (Medium) (CVE-2020-8252)
+### fs.realpath.native may cause buffer overflow (Medium) (CVE-2020-8252)
 
 libuv's realpath implementation incorrectly determined the buffer size which can result in a buffer overflow if the resolved path is longer than 256 bytes.