[1841] Merged value for merging minors is wrong, when the average is exactly N+0.5

[physic]

https://18xx.games/game/132855?action=413

The merged price for SFLi is wrong. It merged to 127, when it should be 141. I suspect the minor merge value of 69.5 was considered by then engine to be "not greater than" 69, but the rules do not support doing integer rounding before performing this calculation.
This issue should only affect merges between minors, since major merges always result in an integer sum.

SFMA is at 68. SFLP is at 71.
Half the sum of 68 and 71 is 69.5, so the minors should merge to 69.
SSFL is at 87. 69 + 87 == 156, which is greater than 141.

4.7.4 merge steps

For minor Corporations, the new value will be the rightmost value which is less than half the sum of the market values of the old Corporations

[roseundy]

Good catch. A fix may require archiving games.

[roseundy]

Just had to remove the superfluous rounding operating