Install pyinstaller hooks from the tip

.gitlab-ci.yml

@@ -212,6 +212,8 @@ windows_exe:
     # Install pyopencl first to use a wheel from silx.org under Windows
     - pip install --find-links http://www.silx.org/pub/wheelhouse/ --trusted-host www.silx.org --prefer-binary pyopencl
     - pip install .[full]
+    # Install pyinstaller hooks from the master (Fix issue with v2020.7 concerning pyopengl support)
+    - pip install git+https://github.com/pyinstaller/pyinstaller-hooks-contrib.git
     # Install pyinstaller
     - pip install pyinstaller
     # Generate fat binary