http2: fix typo in comment

Change-Id: I9c147e3c8f91c3375691503eed70d921f31bd2cc
GitHub-Last-Rev: 462426c8d13030192cacc331dc38465c0ad6a889
GitHub-Pull-Request: golang/net#61
Reviewed-on: https://go-review.googlesource.com/c/net/+/214602
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

http2/transport.go

@@ -93,7 +93,7 @@ type Transport struct {
 	// send in the initial settings frame. It is how many bytes
 	// of response headers are allowed. Unlike the http2 spec, zero here
 	// means to use a default limit (currently 10MB). If you actually
-	// want to advertise an ulimited value to the peer, Transport
+	// want to advertise an unlimited value to the peer, Transport
 	// interprets the highest possible value here (0xffffffff or 1<<32-1)
 	// to mean no limit.
 	MaxHeaderListSize uint32