Uninstall old python first

.gitlab-ci.yml

@@ -121,9 +121,11 @@ build:windows:
     GIT_DEPTH: 5
   before_script:
     - ./docker/install_choco.ps1
+    - choco uninstall python3
     - choco install -y --x64 python3 7zip checksum
     - python --version # | findstr /B "Python 3\.7\." # dont upgrade python on every run. just make sure we're on the right Python
     - pip --version # | findstr /E '\(python 3\.7\)'
+    - python -c "import sys;print(f'{str(64 if sys.maxsize > 2**32 else 32)} bit python\n{sys.platform}')"
     - pip install virtualenv pywin32
     - virtualenv venv
     - venv/Scripts/activate.ps1