job-list: remove invalid test

Problem: Amongst the job-list unit tests is a test that checks that
the "attributes.system" dictionary exists in the jobspec.  However,
RFC14 indicates that it is optional.

Remove this invalid test.

Author: chu11

src/modules/job-list/Makefile.am

@@ -113,7 +113,6 @@ EXTRA_DIST = \
 	test/jobspec/invalid_version.jobspec \
 	test/jobspec/job_name_alt.jobspec \
 	test/jobspec/missing_attributes.jobspec \
-	test/jobspec/missing_attributes_system.jobspec \
 	test/jobspec/missing_resources.jobspec \
 	test/jobspec/missing_tasks.jobspec \
 	test/jobspec/missing_version.jobspec

src/modules/job-list/test/job_data.c

@@ -28,7 +28,6 @@ struct test_jobspec_corner_case {
 } jobspec_corner_case_tests[] = {
     { TEST_SRCDIR "/jobspec/invalid_json.jobspec", -1 },
     { TEST_SRCDIR "/jobspec/missing_attributes.jobspec", -1 },
-    { TEST_SRCDIR "/jobspec/missing_attributes_system.jobspec", -1 },
     { TEST_SRCDIR "/jobspec/invalid_attributes_system_job.jobspec", -1 },
     { TEST_SRCDIR "/jobspec/missing_tasks.jobspec", -1 },
     { TEST_SRCDIR "/jobspec/invalid_tasks_array.jobspec", -1 },