Fixed typo (vi leftover).
There was a trailing :w at a line, which didn't make sense in context
of the sentence/styling. Removed it, because I think it's a leftover
vi command.
CLA: trivial
@@ -230,7 +230,7 @@ The section of the configuration file containing certificate extensions
to be added when a certificate is issued (defaults to B<x509_extensions>
unless the B<-extfile> option is used). If no extension section is
present then, a V1 certificate is created. If the extension section
-is present (even if it is empty), then a V3 certificate is created. See the:w
+is present (even if it is empty), then a V3 certificate is created. See the
L<x509v3_config(5)> manual page for details of the
extension section format.
