tst_qsslkey - handle QT_NO_SSL properly

The recent change handling missing elliptic curves introduced a problem
for '-no-ssl' configuration/build. The first version had some protection,
but it was openssl-specific and required a private feature, thus was
removed. Now the real ifdef must be with QT_NO_SSL

Fixes: QTBUG-88238
Pick-to: 5.15
Change-Id: I6fba26d6ab63850e1468e76f8b234703255a026c
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

tests/auto/network/ssl/qsslkey/tst_qsslkey.cpp

@@ -117,6 +117,7 @@ private:
 
 tst_QSslKey::tst_QSslKey()
 {
+#ifndef QT_NO_SSL
     const QString expectedCurves[] = {
         // See how we generate them in keys/genkey.sh.
         QStringLiteral("secp224r1"),
@@ -139,6 +140,9 @@ tst_QSslKey::tst_QSslKey()
             unsupportedCurves.push_back(requestedEc);
         }
     }
+#else
+    unsupportedCurves = {}; // not unsued anymore.
+#endif
 }
 
 bool tst_QSslKey::fileContainsUnsupportedEllipticCurve(const QString &fileName) const