I could only get that warning string if I explicity imported IO::Socket::SSL in my script.  If I imported Net::SSL just after, it worked.

If the BEGIN { } block doesn't fix it as specified above, try import Net::SSL right after VMware::VIRuntime. 

use VMware::VIRuntime;

use Net::SSL;

There's may be some preference (intended or not) for Net::SSL, or some other change in how LWP determine what SSL socket class to use.

Let me know if either option works.  You may also need to install Net::SSL.