Do not update long horizon conthists when in check

[TheRealGioviok]

I saw this in sf, don't know if its original to them or taken from another engine. Note this heavily interacts with @Yoshie2000 conthist banger patch.

Passed STC

Test  | incheckconthisttweak
Elo   | 5.33 +- 3.19 (95%)
SPRT  | 8.0+0.08s Threads=1 Hash=16MB
LLR   | 2.95 (-2.94, 2.94) [0.00, 3.00]
Games | N: 15584 W: 4141 L: 3902 D: 7541
Penta | [177, 1808, 3606, 2001, 200]

https://ob.cwchess.org/test/1267/

Passed LTC

Test  | incheckconthisttweak
Elo   | 9.69 +- 4.28 (95%)
SPRT  | 40.0+0.40s Threads=1 Hash=64MB
LLR   | 2.95 (-2.94, 2.94) [0.00, 3.00]
Games | N: 7068 W: 1809 L: 1612 D: 3647
Penta | [27, 769, 1758, 940, 40]

https://ob.cwchess.org/test/1272/

Bench: 17487016