fix(NODE-3109): prevent servername from being IP (#2763)

servername should only ever be a hostname. Add a condition
to check if the host is an IP and skip auto setting the servername.

Author: nbbeeken

lib/core/connection/connect.js

@@ -243,7 +243,7 @@ function parseSslOptions(family, options) {
   }
 
   // Set default sni servername to be the same as host
-  if (result.servername == null) {
+  if (result.servername == null && !net.isIP(result.host)) {
     result.servername = result.host;
   }