Suomipeli24: Vision bugs

[lmoureaux]

Describe the bug

• Not all cities are visible after building the Internet
• Sharing maps via diplomacy doesn't appear to update cities that the owner of the Internet couldn't see

To Reproduce
Unclear. Try loading from the save on T104.

Expected behavior
Cities are visible immediately after building The Internet.

Screenshots

Platform and version (please complete the following information):

• OS: Linux
• Freeciv21 version: 3.1-beta.2
• Ruleset/Longturn game (if applicable): Royale/Suomipeli24

Additional context
Reported privately by Mu. Expecting more info next turn (suspecting The Internet will start working and the issue will go away).

[lmoureaux]

On the next turn all cities were visible as expected. However Apollo (built the same turn) wasn't active yet.