crypto/tls: fix typo in tls handshake error

Change-Id: Ia9f39250619ea6e94157efceddfb2e02d35f3ae2
Reviewed-on: https://go-review.googlesource.com/7041
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/crypto/tls/handshake_server.go b/src/crypto/tls/handshake_server.go
index c87da50..7675770 100644
--- a/src/crypto/tls/handshake_server.go
+++ b/src/crypto/tls/handshake_server.go
@@ -229,7 +229,7 @@
 			// The client is doing a fallback connection.
 			if hs.clientHello.vers < c.config.maxVersion() {
 				c.sendAlert(alertInappropriateFallback)
-				return false, errors.New("tls: client using inppropriate protocol fallback")
+				return false, errors.New("tls: client using inappropriate protocol fallback")
 			}
 			break
 		}