Fix TestSQLBackendArrayColumns.testBulkFetch on PostgreSQL

java.lang.AssertionError: expected:<[tst:tags, testschema, acls, versions, tst:bignotes, tst:subjects, misc]> but was:<[testschema, acls, versions, tst:bignotes, misc]>
	at org.junit.Assert.fail(Assert.java:88)
	at org.junit.Assert.failNotEquals(Assert.java:834)
	at org.junit.Assert.assertEquals(Assert.java:118)
	at org.junit.Assert.assertEquals(Assert.java:144)
	at org.nuxeo.ecm.core.storage.sql.TestSQLBackend.testBulkFetch(TestSQLBackend.java:2663)