fix errors in gitlabci yml file

.gitlab-ci.yml

@@ -24,8 +24,8 @@ dune-git-clang:
 dune-git-istl-gcc:
   image: registry.dune-project.org/docker/ci/dune-pdelab-deps:git-debian-10-gcc-8-17
   variables:
-  - DUNECI_CMAKE_FLAGS: "-DBACKEND=ISTL"
-  - DUNECI_CXXFLAGS: "-Wno-deprecated-declarations -Wno-cpp"
+    DUNECI_CMAKE_FLAGS: "-DBACKEND=ISTL"
+    DUNECI_CXXFLAGS: "-Wno-deprecated-declarations -Wno-cpp"
   script:
   - duneci-standard-test
   - dunecontrol --current make -j2 examples
@@ -33,8 +33,8 @@ dune-git-istl-gcc:
 dune-git-petsc-gcc:
   image: registry.dune-project.org/docker/ci/dune-pdelab-deps:git-debian-10-gcc-8-17
   variables:
-  - DUNECI_CMAKE_FLAGS: "-DBACKEND=PETSC"
-  - DUNECI_CXXFLAGS: "-Wno-deprecated-declarations -Wno-cpp"
+    DUNECI_CMAKE_FLAGS: "-DBACKEND=PETSC"
+    DUNECI_CXXFLAGS: "-Wno-deprecated-declarations -Wno-cpp"
   script:
   - duneci-standard-test
   - dunecontrol --current make -j2 examples
@@ -42,8 +42,8 @@ dune-git-petsc-gcc:
 dune-git-eigen-gcc:
   image: registry.dune-project.org/docker/ci/dune-pdelab-deps:git-debian-10-gcc-8-17
   variables:
-  - DUNECI_CMAKE_FLAGS: "-DBACKEND=EIGEN"
-  - DUNECI_CXXFLAGS: "-Wno-deprecated-declarations -Wno-cpp"
+    DUNECI_CMAKE_FLAGS: "-DBACKEND=EIGEN"
+    DUNECI_CXXFLAGS: "-Wno-deprecated-declarations -Wno-cpp"
   script:
   - duneci-standard-test
   - dunecontrol --current make -j2 examples
@@ -51,8 +51,8 @@ dune-git-eigen-gcc:
 dune-git-mtl-gcc:
   image: registry.dune-project.org/docker/ci/dune-pdelab-deps:git-debian-10-gcc-8-17
   variables:
-  - DUNECI_CMAKE_FLAGS: "-DBACKEND=MTL -DMTL_INCLUDE_DIR=/duneci/libs/mtl4"
-  - DUNECI_CXXFLAGS: "-Wno-deprecated-declarations -Wno-cpp"
+    DUNECI_CMAKE_FLAGS: "-DBACKEND=MTL -DMTL_INCLUDE_DIR=/duneci/libs/mtl4"
+    DUNECI_CXXFLAGS: "-Wno-deprecated-declarations -Wno-cpp"
   before_script:
   - git clone https://gitlab.mn.tu-dresden.de/spraetor/mtl4.git /duneci/libs/mtl4
   script: