Fix disk space issue about Github Autobuild

[abitmore]

For Ubuntu build in debug mode, build libraries and programs in a volume which is not the default volume, build others in the default volume.

[abitmore]

Disk space usage when building in debug mode:

5.7G	_build/tests
5.0G	/_build/libraries
5.3G	/_build/programs

868M	_build/tests/CMakeFiles
48K	_build/tests/Makefile
769M	_build/tests/app_test
918M	_build/tests/chain_test
843M	_build/tests/cli_test
4.0K	_build/tests/cmake_install.cmake
777M	_build/tests/es_test
761M	_build/tests/generate_empty_blocks
68M	_build/tests/libdatabase_fixture.a
780M	_build/tests/performance_test

12K	_build/libraries/CMakeFiles
8.0K	_build/libraries/Makefile
442M	_build/libraries/app
707M	_build/libraries/chain
4.0K	_build/libraries/cmake_install.cmake
7.8M	_build/libraries/db
114M	_build/libraries/egenesis
377M	_build/libraries/fc
86M	_build/libraries/net
427M	_build/libraries/plugins
2.2G	_build/libraries/protocol
6.8M	_build/libraries/utilities
676M	_build/libraries/wallet

12K	_build/programs/CMakeFiles
8.0K	_build/programs/Makefile
571M	_build/programs/build_helpers
918M	_build/programs/cli_wallet
4.0K	_build/programs/cmake_install.cmake
1.3G	_build/programs/genesis_util
592M	_build/programs/js_operation_serializer
570M	_build/programs/network_mapper
575M	_build/programs/size_checker
815M	_build/programs/witness_node