ci: set MOZ_FORCE_DISABLE_E10S to work around firefox not working under docker sometimes

packages/common/.gitlab-ci.yml

-image: registry.gitlab.tugraz.at/vpu/webcomponents/common/main:v4
+image: registry.gitlab.tugraz.at/vpu/webcomponents/common/main:v5
 
 before_script:
   - "sed -i 's|git@gitlab.tugraz.at:VPU|../..|g' .gitmodules"

packages/common/.gitlab-ci/Dockerfile

@@ -3,6 +3,9 @@ FROM debian:buster
 ENV LANG C.UTF-8
 ENV DEBIAN_FRONTEND noninteractive
 
+# https://github.com/karma-runner/karma-firefox-launcher/issues/104
+ENV MOZ_FORCE_DISABLE_E10S true
+
 RUN apt-get update && apt-get install -y \
     git \
     curl \

packages/common/.gitlab-ci/build.sh

 #!/bin/bash
 
 set -e
-TAG="registry.gitlab.tugraz.at/vpu/webcomponents/common/main:v4"
+TAG="registry.gitlab.tugraz.at/vpu/webcomponents/common/main:v5"
 sudo docker build --tag "${TAG}" --file "Dockerfile" .
 echo "Now run: sudo docker push '$TAG'"