build: fix default flags for Apple clang

Change-Id: I1f9d15cb7022f91ce7a55f07ddd5693b9e581905
diff --git a/.jenkins.d/00-deps.sh b/.jenkins.d/00-deps.sh
index 33c0537..e460d3a 100755
--- a/.jenkins.d/00-deps.sh
+++ b/.jenkins.d/00-deps.sh
@@ -31,7 +31,7 @@
 FORMULAE=(boost openssl pkgconf)
 case $JOB_NAME in
     *code-coverage)
-        APT_PKGS+=(lcov)
+        APT_PKGS+=(lcov libjson-xs-perl)
         ;;
     *Docs)
         ;;