update docker image certificates for downloading .clang-format

.gitlab-ci.yml

@@ -9,7 +9,8 @@ clang_format:
     - master   
   before_script:     
     - apt-get update     
-    - apt-get install --yes --no-install-recommends wget git clang-format-11   
+    - apt-get install --yes --no-install-recommends wget ca-certificates git clang-format-11   
+    - update-ca-certificates
   script:     
     - wget -c --output-document=.clang-format https://invent.kde.org/frameworks/extra-cmake-modules/raw/master/kde-modules/clang-format.cmake
     - git diff-tree --no-commit-id --name-only -r origin/$CI_MERGE_REQUEST_TARGET_BRANCH_NAME -r $CI_COMMIT_SHA | grep -v -P '[.](c|cc|cpp|hpp|h)$'| xargs clang-format-11 -i