config reload freezes SONiC if json is syntactically incorrect

[MaratGubaiev]

Description

config reload config.json freezes SONiC if config.json is syntactically incorrect, like a comma is missing.

Steps to reproduce the issue:

1. Create syntactically incorrect config.json file.
2. config reload config.json

Describe the results you received:

Terminal freezes. After reopening the terminal SONiC commands (inc. reboot) cause to freezing the terminal again. Linux commands (like /usr/sbin/reboot) work.

Describe the results you expected:

Some "syntax error" message without any consequences.

Output of show version:

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Output of show techsupport:

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Additional information you deem important (e.g. issue happens only occasionally):