Remove mentions of SSL 3 in documentation

And some s,SSL,TLS, in the same paragraphs.
Changing SSL to TLS in the whole codebase looks odd given classes are
still called QSsl*, but may be worth considering at some point.

Pick-to: 6.3 6.2
Change-Id: I06dfcd99c1f6ac9e029e1914363344b3705d871f
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

src/network/access/qnetworkrequest.cpp

@@ -711,9 +711,8 @@ QSslConfiguration QNetworkRequest::sslConfiguration() const
 /*!
     Sets this network request's SSL configuration to be \a config. The
     settings that apply are the private key, the local certificate,
-    the SSL protocol (SSLv2, SSLv3, TLSv1.0 where applicable), the CA
-    certificates and the ciphers that the SSL backend is allowed to
-    use.
+    the TLS protocol (e.g. TLS 1.3), the CA certificates and the ciphers that
+    the SSL backend is allowed to use.
 
     \sa sslConfiguration(), QSslConfiguration::defaultConfiguration()
 */

src/network/ssl/qsslsocket.cpp

@@ -18,10 +18,10 @@
 
     QSslSocket establishes a secure, encrypted TCP connection you can
     use for transmitting encrypted data. It can operate in both client
-    and server mode, and it supports modern SSL protocols, including
-    SSL 3 and TLS 1.2. By default, QSslSocket uses only SSL protocols
+    and server mode, and it supports modern TLS protocols, including
+    TLS 1.3. By default, QSslSocket uses only TLS protocols
     which are considered to be secure (QSsl::SecureProtocols), but you can
-    change the SSL protocol by calling setProtocol() as long as you do
+    change the TLS protocol by calling setProtocol() as long as you do
     it before the handshake has started.
 
     SSL encryption operates on top of the existing TCP stream after