fix ci

.github/workflows/ci.yml

@@ -41,7 +41,7 @@ jobs:
           echo "CC=clang-${{ matrix.config.version }}" >> $GITHUB_ENV
           echo "CXX=clang++-${{ matrix.config.version }}" >> $GITHUB_ENV
       - name: Setup Git # update git to support sparse-checkout for gcc:7 images
-        if: contains(env.GITHUB_JOB_CONTAINER_IMAGE, 'gcc:7') 
+        if: matrix.config.compiler == 'gcc' && matrix.config.version == 7
         run: |
           sudo add-apt-repository ppa:git-core/ppa -y
           sudo apt-get update