JIRA doesn't allow you to fiddle with the reporter field. I had the exact same issue with the JIRA plugin for ReadyAPI 1.6.0 and 1.7.0 and the solution for me was to make the reporter field optional instead of required in JIRA. Since the plugin uses credentials to commit the issue to JIRA the reporter will automatically be set to whatever user is configured here.
There seems to be no way to leave the reporter field unset even though it is set to optional. The logged in user will be set as reporter.
The only limitation to this is that you cannot create a ticket with some other reporter then the user you use to authenticate with JIRA.
