When the HttpSolrClient is formatting a V2Request, it needs to change the endpoint from the default "/solr/..." to "/api/...". It does so by simply calling String.replace, which replaces the first instance of "/solr" in the URL with "/api".
In the case where the host's address starts with "solr" and the HTTP protocol is appended, this call changes the address for the request. Example:
if baseUrl is "http://solr-host.com/8983/solr", this call will change to "http:/api-host.com:8983/solr"
We should use a regex pattern to ensure that we're replacing the correct portion of the URL.