fix typo

Author: neoscie

CHANGELOG.md

@@ -31,7 +31,7 @@ and adheres to a project-specific [Versioning](/README.md).
 - S3878: Arrays should not be created for params parameters
 - S4545: "DebuggerDisplayAttribute" strings should reference existing members
 - S4663: Comments should not be empty
-  -S5856: Regular expressions should be syntactically valid
+- S5856: Regular expressions should be syntactically valid
 
 ### Removed