Removed unused SSL Registry and an empty unit
Small code clean ups to remove unused GSSLRegistry
and the empty unit IdServerIOHandlerSSLOpenSSL.
Maybe it's time to remove .NET too?
Even if external tools make use of it, they could still create an own list and register the SLLIOHandler.
Support for .NET and pre-Unicode compilers is already slated to be removed in Indy 11 (https://github.com/IndySockets/Indy/issues/131 and https://github.com/IndySockets/Indy/issues/132). It has already been implemented - what is currently in the "Restructure" branch in GitHub will eventually be rebranded as Indy 11, once some pending things have been finalized and the branch is updated with the latest code from my working copy.