Fixing pygdal installation (again, again)

.gitlab-ci.yml

@@ -11,7 +11,7 @@ test:
   stage: test
   script:
     - apt-get update
-    - apt-get install -y libgdal-dev
+    - apt-get install -y libgdal-dev g++
     - pip3 install "pygdal==$(gdal-config --version).*"
     - pip3 install -r requirements-test.txt
     - pip3 install -r requirements-dev.txt