Updated missing files and modinfo

- Include the fix made by SpatialX.

Trying to implement the fix proposed by Ouija

Did not expect Covid-19 to last that long. I put the back the harder version which was more stable too.

-Changed expectation value of new plague to one every 30 turns. The probability of new plague any turn is about 3.3%

- Fix a LUA bug that was indexing empty tables
- Trying to fix compatibility issues with the new CiV 6 patch of 28.01.2021

- New plague chance of appearing divided by 4

- New plague can appear in maximum one city at a time. One city is taken randomly in the pool of possible cities. The expectation of new plague increased linearly with the number of cities and I want the expectation of new plague appearing to be the same no matter the number of cities. The spread mechanic of existing plague to other cities did not change.

- Reduce the chance of plague starting by 30%
- Plague spreading now depends on the era
- Fix a bug that allowed the supply convoy to gain experience