net/http/cookiejar: remove duplicate words from comments

Change-Id: Id44f587199683fd8018865af1c2442f9f74e0dad
GitHub-Last-Rev: 35b1ab8
GitHub-Pull-Request: #54495
Reviewed-on: https://go-review.googlesource.com/c/go/+/424434
Reviewed-by: hopehook <hopehook@qq.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Run-TryBot: hopehook <hopehook@qq.com>
Reviewed-by: Joedian Reid <joedian@golang.org>

src/net/http/cookiejar/jar.go

@@ -465,7 +465,7 @@ func (j *Jar) domainAndType(host, domain string) (string, bool, error) {
 		// dot in the domain-attribute before processing the cookie.
 		//
 		// Most browsers don't do that for IP addresses, only curl
-		// version 7.54) and and IE (version 11) do not reject a
+		// version 7.54) and IE (version 11) do not reject a
 		//     Set-Cookie: a=1; domain=.127.0.0.1
 		// This leading dot is optional and serves only as hint for
 		// humans to indicate that a cookie with "domain=.bbc.co.uk"