PRC must not add semicolon in <option> value of StartupPack message

Bug Report

The inclusion of a semicolon in the <option> element results in ips for iRODS 5 including a semicolon in client app names.

Line 325 in 4315b8d

main_message.option = "{};{}".format(main_message.option, REQUEST_NEGOTIATION)

This happens under the following conditions:

The PRC is loading irods_environment.json to establish a connection
The irods_environment.json file defines "irods_client_server_negotiation": "request_server_negotiation"

Here's an example of a valid value for <option>. This was produced by ils.

<option>ilsrequest_server_negotiation</option>

Originally reported at irods/irods#8530.