http2: update curl download location in Dockerfile

Change-Id: Ifeef1948df83f104396c43c15f07a2d146208533
GitHub-Last-Rev: c8e17d64d127bd2fc5405b4d82ea0b3a05e8138f
GitHub-Pull-Request: golang/net#99
Reviewed-on: https://go-review.googlesource.com/c/net/+/309949
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/http2/Dockerfile b/http2/Dockerfile
index 53fc525..8512245 100644
--- a/http2/Dockerfile
+++ b/http2/Dockerfile
@@ -38,7 +38,7 @@
 RUN make install
 
 WORKDIR /root
-RUN wget http://curl.haxx.se/download/curl-7.45.0.tar.gz
+RUN wget https://curl.se/download/curl-7.45.0.tar.gz
 RUN tar -zxvf curl-7.45.0.tar.gz
 WORKDIR /root/curl-7.45.0
 RUN ./configure --with-ssl --with-nghttp2=/usr/local