ci: use https URL in git clone command

Change-Id: I35c7ffa2e03957084b74c2db183780a70b5aab27
diff --git a/.jenkins.d/01-ndn-cxx.sh b/.jenkins.d/01-ndn-cxx.sh
index e5bdda8..3249e4c 100755
--- a/.jenkins.d/01-ndn-cxx.sh
+++ b/.jenkins.d/01-ndn-cxx.sh
@@ -18,7 +18,7 @@
 fi
 
 sudo rm -rf ndn-cxx-latest
-git clone --depth 1 git://github.com/named-data/ndn-cxx ndn-cxx-latest
+git clone --depth 1 https://github.com/named-data/ndn-cxx.git ndn-cxx-latest
 LATEST_VERSION=$(git -C ndn-cxx-latest rev-parse HEAD 2>/dev/null || echo UNKNOWN)
 
 if [[ $INSTALLED_VERSION != $LATEST_VERSION ]]; then