perlrebackslash: Add missing paren to example

pod/perlrebackslash.pod

@@ -603,7 +603,7 @@ linebreak sequence by Unicode. This includes all characters matched by
 C<\v> (vertical whitespace), and the multi character sequence C<"\x0D\x0A">
 (carriage return followed by a line feed, sometimes called the network
 newline; it's the end of line sequence used in Microsoft text files opened
-in binary mode). C<\R> is equivalent to C<< (?>\x0D\x0A)|\v) >>. Since
+in binary mode). C<\R> is equivalent to C<< (?>\x0D\x0A|\v) >>. Since
 C<\R> can match a sequence of more than one character, it cannot be put
 inside a bracketed character class; C</[\R]/> is an error; use C<\v>
 instead.  C<\R> was introduced in perl 5.10.0.