[GitLabCI] Update CI to get aidge_core addr.

.gitlab/ci/build.gitlab-ci.yml

@@ -7,6 +7,10 @@ build:ubuntu_cpp:
   script:
     - mkdir -p build_cpp
     - mkdir -p install_cpp
+    - BASE_URL=`echo $CI_REPOSITORY_URL | sed "s;\/*$CI_PROJECT_PATH.*;;"`
+    - REPO_URL="$BASE_URL/aidge/aidge_core.git"
+    - echo REPO_URL
+    - echo BASE_URL
     - cd build_cpp
     - cmake -DCMAKE_INSTALL_PREFIX:PATH=../install_cpp -DCMAKE_BUILD_TYPE=Debug -DWERROR=ON ..
     - make -j4 all install