Improve Android OpenSSL settings UI

The android settings just state "Android OpenSSL setting" but don't explain what they are for and whether i really need them. Some more explainations would help here.

I changed the default path to my SDK directory, as i thought this would be part of the SDK... afterwards i saw the download button and used that, ignored the message box and my android-sdk directory was gone...

It was all my fault, nothing to discuss, but it should be more explicit in my opinion or even better don't delete it at all, just allow downloading a new one.