Tweak piece values for archbishop and chancellor

Tweak piece values for archbishop and chancellor

capablanca STC
LLR: 2.96 (-2.94,2.94) [0.00,10.00]
Total: 4702 W: 1895 L: 1747 D: 1060
http://35.161.250.236:6543/tests/view/5d07f4246e23db34f4206bee

capablanca LTC
LLR: 2.95 (-2.94,2.94) [0.00,10.00]
Total: 5260 W: 2022 L: 1870 D: 1368
http://35.161.250.236:6543/tests/view/5d0a560a6e23db34f4206bfe

modern STC
LLR: 2.95 (-2.94,2.94) [-10.00,5.00]
Total: 2329 W: 782 L: 746 D: 801
http://35.161.250.236:6543/tests/view/5d09e6a26e23db34f4206bfc

chancellor STC
LLR: 2.97 (-2.94,2.94) [-10.00,5.00]
Total: 3677 W: 1225 L: 1197 D: 1255
http://35.161.250.236:6543/tests/view/5d07fa7b6e23db34f4206bf7