Going from Observe to Take loses buttons on top bar

[jwrober]

Describe the bug
If you open a single player game and do a global observe, you correctly lose access to some buttons on the top bar such as research, economy and tax rates. If you observe

To Reproduce
Steps to reproduce the behavior:

1. Open a single player game
2. In the chat line do an /observe
3. Notice that Research, Economy and Tax Rates disappear -- good
4. In the chat line do an /observe <player>
5. Notice that you get back Tax Rates, but not Research or Economy -- bad
6. In the chat line do a /take <player>
7. Notice that you don't get back Research or Economy -- bad

The same thing happens if you go from global observe back to /take. If I do an /observe <player> it works as expected I keep all the buttons on the top bar. So it is something with global observe.

Expected behavior
We don't lose buttons into cyberspace.

Screenshots
I didn't capture any. You can see it for your self pretty easily.

Platform and version (please complete the following information):

• OS: Linux
• Freeciv21 version: Master at 68b5063
• Ruleset/Longturn game (if applicable): Classic, but not sure its relevant

Additional context
I found it while playing around and testing PR #1287

[lmoureaux]

Finally someone notices and files an issue 😅 (I had seen this before but forgot about it)

[jwrober]

The same thing happens between /take and does not have to involve /observe