HELP SHOW LOAD doesn't say SHOW LOAD cannot be used for stream load

[creatstar]

Describe the bug
HELP SHOW LOAD doesn't say SHOW LOAD cannot be used for stream load.

To Reproduce
Steps to reproduce the behavior:

1. help show load

Expected behavior
The stream load tasks are not showed in SHOW LOAD command. This content should be included in "HELP SHOW LOAD".

[yangzhg]

Stream load cannot show in SHOW LOAD statment , because of stream load is a synchronized http api

[creatstar]

Yes, SHOW LOAD doesn't support Stream Load should be indicated in the Help Text. Otherwise, the reader would not get that point.