Replace JENKINS_URL with JENKINS_PUBLIC_URL

To ensure tf-a-job-configs can run on both OpenCI
and Arm Test CI, JENKINS_URL has been replaced with
JENKINS_PUBLIC_URL, as JENKINS_URL is a reserved
private URL in Arm infrastructure.

JENKINS_PUBLIC_URL is a system-wide environment
variable and was configured in:
Manage Jenkins > System > Global Properties

Default values:
OpenCI Production Jenkins: https://ci.trustedfirmware.org/
OpenCI Staging Jenkins: https://ci.staging.trustedfirmware.org/
Arm Test CI Jenkins: https://jenkins.openci-test.arm.com/

Signed-off-by: Saheer Babu <saheer.babu@arm.com>
Change-Id: I546cf44d21ba7b7229b895d5c78b41019711895e
(cherry picked from commit e77abb3fb86a7e3f34c1ef582b9ea226e0da0ef6)
diff --git a/ci/run-jjb.py b/ci/run-jjb.py
index c003b53..7fba293 100755
--- a/ci/run-jjb.py
+++ b/ci/run-jjb.py
@@ -10,6 +10,8 @@
 from distutils.spawn import find_executable
 
 
+jenkins_url = os.environ.get("JENKINS_PUBLIC_URL", "https://ci.trustedfirmware.org")
+
 def findparentfiles(fname):
     filelist = []
     newlist = []
diff --git a/eclair/post_gerrit_comment.sh b/eclair/post_gerrit_comment.sh
index 7388416..9d2042f 100755
--- a/eclair/post_gerrit_comment.sh
+++ b/eclair/post_gerrit_comment.sh
@@ -13,7 +13,7 @@
 SCRIPT_DIR="$(cd "$(dirname "$0")" ; echo "${PWD}")"
 
 # Don't post comments if run on the staging server.
-if echo "$JENKINS_URL" | grep -q "ci\.staging"; then
+if echo "$JENKINS_PUBLIC_URL" | grep -q "ci\.staging"; then
     should_post_comment=0
 fi