Define openssl symbol resolution warning function only if necessary

Without library support we don't try to load any symbols and the
function is unused. This results in a compiler warning.

Change-Id: I82ad46a478debe48cf9a8311f5e5ec299baa1af8
Reviewed-by: Richard J. Moore <rich@kde.org>

src/network/ssl/qsslsocket_openssl_symbols.cpp

@@ -119,10 +119,13 @@ void qsslSocketUnresolvedSymbolWarning(const char *functionName)
     qCWarning(lcSsl, "QSslSocket: cannot call unresolved function %s", functionName);
 }
 
+#ifndef QT_NO_LIBRARY
 void qsslSocketCannotResolveSymbolWarning(const char *functionName)
 {
     qCWarning(lcSsl, "QSslSocket: cannot resolve %s", functionName);
 }
+#endif
+
 }
 
 #endif // QT_LINKED_OPENSSL