CLI tools does not report API connection error when JSON output is enabled

[atodorov-storpool]

Description

CLI tools should have consistency in error reporting.

$ onehook list ; echo $?
Failed to open TCP connection to localhost:2633 (Connection refused - connect(2) for "localhost" port 2633)
255

$ onehook list --xml ; echo $?
Failed to open TCP connection to localhost:2633 (Connection refused - connect(2) for "localhost" port 2633)
255

$ onehook list --json ; echo $?
0

To Reproduce

• stop the opennebula service
• issue a cli tool with --json argument
• no output, no error message and exit code '0'

Expected behavior
An error message should be displayed and an exit code should be set

Details

• Affected Component: [cli]
• Hypervisor: [KVM]
• Version: [6.4.4]

Additional context

Progress Status

• Code committed
• Testing - QA
• Documentation (Release notes - resolved issues, compatibility, known issues)