Add SPDX license identifier to fail1.adb also.

Oops, missed one file from the first go.
1 files changed, 2 insertions(+), 0 deletions(-)

M robot/test_sources/fail1/fail1.adb
M robot/test_sources/fail1/fail1.adb +2 -0
@@ 13,6 13,8 @@ 
 -- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 -- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 --
+-- SPDX-License-Identifier: ISC
+--
 
 with Ada.Text_IO;
 use Ada.Text_IO;