CI: Try to build the rust things before to have the stdout/stderr in the CI logs

.gitlab-ci.yml

@@ -31,6 +31,8 @@
         - ./rustup.sh -y --default-toolchain beta
         - source ~/.cargo/env
     script:
+        - ~/.cargo/bin/cargo build --manifest-path src/rust/liblektor-rs/Cargo.toml
+        - ~/.cargo/bin/cargo build --manifest-path src/rust/amadeus-rs/Cargo.toml
         - cmake -Bbuild -DCMAKE_RUST_COMPILER=~/.cargo/bin/cargo -DCMAKE_C_COMPILER=${c_compiler} -DCMAKE_CXX_COMPILER=${cxx_compiler} && make -Cbuild
 
 variables: