fix: may be nullable types

Author: Boris Dorofeev

src/types/job/Job.logs.ts

@@ -12,7 +12,7 @@ export function createLogsFC(
       name: `${typePrefix}JobLogs`,
       fields: {
         count: 'Int',
-        items: '[String!]',
+        items: '[String]',
       },
       // args: {}, // TODO: start end
     }),

src/types/job/Job.ts

@@ -17,7 +17,7 @@ export function getJobTC(sc: SchemaComposer<any>, opts: Options) {
       timestamp: 'Date',
       attemptsMade: 'Int',
       failedReason: 'JSON',
-      stacktrace: '[String!]',
+      stacktrace: '[String]',
       returnvalue: 'JSON',
       finishedOn: 'Date',
       processedOn: 'Date',