ci: pull libssh2 from www.libssh2.org

libssh2.org and www.libssh2.org were previously identical; now this is a
redirect.

ci/docker/centos7

@@ -18,7 +18,7 @@ RUN yum install -y \
 
 FROM yum AS libssh2
 RUN cd /tmp && \
-    curl https://libssh2.org/download/libssh2-1.8.0.tar.gz | tar -xz && \
+    curl --location --silent --show-error https://www.libssh2.org/download/libssh2-1.8.0.tar.gz | tar -xz && \
     cd libssh2-1.8.0 && \
     ./configure && \
     make && \

ci/docker/centos8

@@ -20,7 +20,7 @@ RUN yum install -y \
 
 FROM yum AS libssh2
 RUN cd /tmp && \
-    curl https://libssh2.org/download/libssh2-1.8.0.tar.gz | tar -xz && \
+    curl --location --silent --show-error https://www.libssh2.org/download/libssh2-1.8.0.tar.gz | tar -xz && \
     cd libssh2-1.8.0 && \
     ./configure && \
     make && \

ci/docker/focal

@@ -49,8 +49,7 @@ RUN cd /tmp && \
 
 FROM mbedtls AS libssh2
 RUN cd /tmp && \
-    curl --insecure --location --silent --show-error https://www.libssh2.org/download/libssh2-1.9.0.tar.gz | \
-        tar -xz && \
+    curl --location --silent --show-error https://www.libssh2.org/download/libssh2-1.9.0.tar.gz | tar -xz && \
     cd libssh2-1.9.0 && \
     mkdir build build-msan && \
     cd build && \

ci/docker/xenial

@@ -41,8 +41,7 @@ RUN cd /tmp && \
 
 FROM mbedtls AS libssh2
 RUN cd /tmp && \
-    curl --insecure --location --silent --show-error https://www.libssh2.org/download/libssh2-1.8.2.tar.gz | \
-    tar -xz && \
+    curl --location --silent --show-error https://www.libssh2.org/download/libssh2-1.8.2.tar.gz | tar -xz && \
     cd libssh2-1.8.2 && \
     CFLAGS=-fPIC cmake -G Ninja -DBUILD_SHARED_LIBS=ON -DCRYPTO_BACKEND=Libgcrypt . && \
     ninja install && \