Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -18,7 +18,7 @@ workflow:
   stage: build
   script:
     # Install prerequisite for git-gui and gitk
-    - echo "proxy=" | sudo tee -a /etc/yum.conf
+    - echo "proxy=_none_" | sudo tee -a /etc/yum.conf
     - sudo yum -y install tcl-devel tk-devel
     # Install recent version of python required to build meson that is a requirement for building chain of git
     - curl -s -L -o python.zip https://gitlab.synchrotron-soleil.fr/software-control-system/devtools/python3/-/jobs/artifacts/${PYTHON_VERSION}/download?job=${PLATFORM}