bionic-amd64-tf-a-build: remove flexnet license variable

The variable ARMLMD_LICENSE_FILE is used by Arm products to point to
the (flexnet) license server [1], which  it is not needed during build
time. At run time, it is set by the CI [2,3] so remove this variable
from the Dockerfile.

[1] https://developer.arm.com/documentation/dui0040/d/apas05s01
[2] https://git.trustedfirmware.org/ci/tf-a-job-configs.git/tree/tf-a-builder.yaml#n41
[3] https://git.trustedfirmware.org/ci/tf-a-job-configs.git/tree/tf-a-builder/builders.sh#n162

Signed-off-by: Leonardo Sandoval <leonardo.sandoval@linaro.org>
Change-Id: Ia269115acae67ec7cbcb2c07796e1f2bf2a293a9
diff --git a/bionic-amd64-tf-a-build/Dockerfile b/bionic-amd64-tf-a-build/Dockerfile
index e719574..dc6a24c 100644
--- a/bionic-amd64-tf-a-build/Dockerfile
+++ b/bionic-amd64-tf-a-build/Dockerfile
@@ -1,8 +1,6 @@
 FROM ubuntu:bionic
 
 # Environment variables used by CI scripts
-ENV ARMLMD_LICENSE_FILE=27000@ci.trustedfirmware.org
-
 ENV DEBIAN_FRONTEND=noninteractive
 ENV NVM_DIR=/usr/local/nvm
 ENV TOOLS_DIR=/home/buildslave/tools
diff --git a/bionic-amd64-tf-a-build/tf-environment.install b/bionic-amd64-tf-a-build/tf-environment.install
index 1a66804..3c73724 100755
--- a/bionic-amd64-tf-a-build/tf-environment.install
+++ b/bionic-amd64-tf-a-build/tf-environment.install
@@ -2,7 +2,6 @@
 
 set -e
 
-env | grep ARMLMD_LICENSE_FILE  >> /etc/environment
 env | grep NVM_DIR >> /etc/environment
 env | grep PLANTUML_JAR_PATH >> /etc/environment
 env | grep TOOLS_DIR >> /etc/environment