log_curl_debug messages convey misleading data payloads

[jason-matthew]

json.dumps() is leveraged twice prior to writing the request's data payload.

1. atlassian-python-api/atlassian/rest_client.py

   Line 160 in 09ff44a

   data = None if not data else dumps(data)

2. atlassian-python-api/atlassian/rest_client.py

   Line 119 in 09ff44a

   data='' if not data else "--data '{0}'".format(dumps(data)),

Logging statements are not accurate curl statements. Note double quotes are being escaped.
2020-09-16 12:15:10,429 DEBUG curl --silent -X POST -H 'Content-Type: application/json' -H 'Accept: application/json' --data '"{\"body\": {\"storage\": {\"representation\": \"storage\",

Using these curl statements complicates atlassian-python-api debugging given API responses convey a different error from what occurred during python execution
{"statusCode":400,"message":"Can not instantiate value of type [simple type, class com.atlassian.confluence.api.model.content.Content] from JSON String; no single-String constructor/factory method","reason":"Bad Request"}

[eli-halych]

curl --silent is another problem - it mutes error messages, which doesn't make sense if you want to debug since you definitely want to see them

[gonchik]

Replaced --silent with --show-error so cURL exposes server errors.