core: revert "manager: do not set up signals in test mode"
This reverts commit
5aa1054521596c3d268db5f4aff9f2b69647ffc9.
Fixes test-execute
$ sudo make check TESTS=test-execute
...
$ cat test-execute.log
+ test /tmp/test-exec_workingdirectory = /tmp/test-exec_workingdirectory
Test timeout when testing exec-workingdirectory.service
exec-workingdirectory.service
UMask: 0022
WorkingDirectory: /tmp/test-exec_workingdirectory
RootDirectory: /
NonBlocking: no
PrivateTmp: no
PrivateNetwork: no
PrivateDevices: no
ProtectHome: no
ProtectSystem: no
IgnoreSIGPIPE: yes
RuntimeDirectoryMode: 0755
StandardInput: null
StandardOutput: inherit
StandardError: inherit
FAIL test-execute (exit status: 1)