fix(schema): avoid `function_clause` error when compacting errors
Fixes https://emqx.atlassian.net/browse/EMQX-10168
The bridge probe API displayed the typecheck errors for the new
timeout duration types correctly, but when an user tried to create the
bridge anyway a `function_clause` error was raised when trying to
compact hocon errors:
```
09:47:19.045 [warning] [exception: :error, path: '/bridges', reason: {:case_clause, {:error, {:config_update_crashed, :function_clause}}}, stacktrace: [{:emqx_bridge_api, :create_or_update_bridge, 4, [file: '/home/thales/dev/emqx/emqx/apps/emqx_bridge/src/emqx_bridge_api.erl', line: 602]}, {:minirest_handler, :apply_callback, 3, [file: '/home/thales/dev/emqx/emqx/deps/minirest/src/minirest_handler.erl', line: 111]}, {:minirest_handler, :handle, 2, [file: '/home/thales/dev/emqx/emqx/deps/minirest/src/minirest_handler.erl', line: 44]}, {:minirest_handler, :init, 2, [file: '/home/thales/dev/emqx/emqx/deps/minirest/src/minirest_handler.erl', line: 27]}, {:cowboy_handler, :execute, 2, [file: '/home/thales/dev/emqx/emqx/deps/cowboy/src/cowboy_handler.erl', line: 41]}, {:cowboy_stream_h, :execute, 3, [file: '/home/thales/dev/emqx/emqx/deps/cowboy/src/cowboy_stream_h.erl', line: 318]}, {:cowboy_stream_h, :request_process, 3, [file: '/home/thales/dev/emqx/emqx/deps/cowboy/src/cowboy_stream_h.erl', line: 302]}, {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 240]}]]
```
This fixes the issue so that both APIs return more friendly error messages.
cc8631223e