Use a locally-sourced image for Windows builds

.gitlab-ci.yml

@@ -5,9 +5,10 @@ cache:
 
 before_script:
   - echo Current working directory is $(pwd)
+  - echo Current user is $(whoami)
   - qmake --version
   - gcc --version
-  - apt-get install --no-install-recommends -y upx zip unzip
+  - sudo apt-get install --no-install-recommends -y upx zip unzip
   - cd scripts
   - ./configure_ubuntu.sh
   - cd ..
@@ -27,7 +28,7 @@ build linux x86_64:
       - bin/
 
 build windows i686:
-  image: fffaraz/qt
+  image: ${CI_REGISTRY_IMAGE}/builder-windows-i686
   stage: build
   tags:
     - docker