tst_QSslSocket: remove #if openssl check for a definition

The declaration was moved out of the #if QT_CONFIG(openssl) block at
some point, but the definition was not. This caused compilation errors
when building without OpenSSL configured.

Pick-to: 6.6 6.5
Change-Id: I41ed85fd57f5a912498e0f2517761b81a7b8673c
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

tests/auto/network/ssl/qsslsocket/tst_qsslsocket.cpp

@@ -166,9 +166,7 @@ private slots:
     void protocol();
     void protocolServerSide_data();
     void protocolServerSide();
-#if QT_CONFIG(openssl)
     void serverCipherPreferences();
-#endif
     void setCaCertificates();
     void setLocalCertificate();
     void localCertificateChain();