HttpClient 4.3 had three static variables in org.apache.http.conn.ssl.SSLConnectionSocketFactory:
org.apache.http.conn.ssl.SSLConnectionSocketFactory
I read all this and nothing worked for me, here's what saved my day: https://stackoverflow.com/a/36507502/3090309
I was using:
compile group: 'org.apache.httpcomponents', name: 'httpclient', version: '4.5.2'