Azure: Allow to not provide tests to be ignored

As for now, a list of tests which will be ignored by Pytest is
mandatory. But actually, a list of tests to run is explicitly set
in yaml config. And thus, 'ignore' list should be an optional field.

This simplifies tests definitions to drop extra stuff.

Fixes: https://pagure.io/freeipa/issue/8202

Signed-off-by: Stanislav Levin <slev@altlinux.org>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>

ipatests/azure/azure-run-tests.sh

@@ -10,6 +10,8 @@ server_password=Secret123
 
 # Normalize spacing and expand the list afterwards. Remove {} for the single list element case
 tests_to_run=$(eval "echo {$(echo $TESTS_TO_RUN | sed -e 's/[ \t]+*/,/g')}" | tr -d '{}')
+tests_to_ignore=
+[[ -n "$TESTS_TO_IGNORE" ]] && \
 tests_to_ignore=$(eval "echo --ignore\ {$(echo $TESTS_TO_IGNORE | sed -e 's/[ \t]+*/,/g')}" | tr -d '{}')
 tests_to_dedicate=
 [[ -n "$TESTS_TO_DEDICATE" ]] && \
@@ -47,7 +49,8 @@ if [ "$install_result" -eq 0 ] ; then
 	ipa-test-task --help
 	ipa-run-tests --help
 
-	ipa-run-tests ${tests_to_ignore} \
+	ipa-run-tests \
+            ${tests_to_ignore} \
             ${tests_to_dedicate} \
             --slices=${SYSTEM_TOTALJOBSINPHASE:-1} \
             --slice-num=${SYSTEM_JOBPOSITIONINPHASE:-1} \