Fix typo in NEWS

“--dry-run” starts with two dashes.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

NEWS

@@ -94,7 +94,7 @@ Version 2.4.1
 *(Released Wed, 09 Mar 2011)*
 
 Emergency bug-fix release. ``tools/cfgupgrade`` was broken and overwrote
-the RAPI users file if run twice (even with ``-dry-run``).
+the RAPI users file if run twice (even with ``--dry-run``).
 
 The release fixes that bug (nothing else changed).