Fixed indention bug in .gitlab-ci.yml

4 jobs for gitlab-runner in 10 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
failed #283835
build

00:00:10

failed #283834
build

00:00:14

failed #283784
build

00:00:17

 
  Test
skipped #283785
test
 
Name Stage Failure
failed
build Build
CMAKE_CXX_COMPILER_ENV_VAR
CMake Error: Error required internal CMake variable not set, cmake may be not be built correctly.
Missing variable is:
CMAKE_CXX_COMPILER
CMake Error: Could not find cmake module file: /tmp/cz7/Spectral/build/CMakeFiles/2.8.12.2/CMakeCXXCompiler.cmake
CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage
CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage
-- Configuring incomplete, errors occurred!
ERROR: Job failed: command terminated with exit code 1