logs: info only if issues are disabled

lib/platform/github/index.js

@@ -605,8 +605,12 @@ async function ensureIssue(title, body) {
       return 'created';
     }
   } catch (err) /* istanbul ignore next */ {
+    if (err.message.startsWith('Issues are disabled for this repo')) {
+      logger.info(`Could not create issue: ${err.message}`);
+    } else {
       logger.warn(expandError(err), 'Could not ensure issue');
     }
+  }
   return null;
 }