Non-deterministic test test_gp_applet()

The test test_gp_applet() is non-deterministic since it depends on the hash of the first certificate not machine neither of the 6 bytes in the example blob. I think we should find a better way to test this:

    /* This part should be generate from certificate hash, which should
     * overwrite default values in template */
    g_assert_cmpint(pbRecvBuffer[15], !=, 0x00);
    g_assert_cmpint(pbRecvBuffer[16], !=, 0x19);
    g_assert_cmpint(pbRecvBuffer[17], !=, 0x00);
    g_assert_cmpint(pbRecvBuffer[18], !=, 0x52);
    g_assert_cmpint(pbRecvBuffer[19], !=, 0x89);
    g_assert_cmpint(pbRecvBuffer[20], !=, 0x0E);

https://gitlab.freedesktop.org/spice/libcacard/blob/master/tests/common.c#L940