[ZEPPELIN-1868]fix to not shows up the login button on Anonymous mode.

[astroshim]

What is this PR for?

This PR fixs to not shows up the login button on Anonymous mode.

What type of PR is it?

Bug Fix

What is the Jira issue?

https://issues.apache.org/jira/browse/ZEPPELIN-1868

How should this be tested?

1. Give permission on note.
2. Turn off the shiro.
3. Delete note that you made on 1.
4. Then you can see the login button like as screen shot.

Screenshots (if appropriate)

Questions:

• Does the licenses files need update? no
• Is there breaking changes for older versions? no
• Does this needs documentation? no

[AhyoungRyu]

Yeah it makes sense. Tested and it's working well 👍

[soralee]

@astroshim It's great work! I will test it!

But, I would like to suggest one thing.
According to what I understand, your screenshot and Then you can see the login button like as screen shot. describes the content before fixing bug in this PR description, right?

I think in this part, It makes confusing for your description of PR. (AFAIK, In general, the description of the PR describes the content after the bug has been fixed.)

So, it would be clear if there is content after fixing the bug 😃
What do you think?

[soralee]

Tested and It works as expected like below!!

[Before]

[After]

[astroshim]

@soralee Thank you for reviewing and commenting!!

[AhyoungRyu]

LGTM. Merge if there are no more comments