depth: 9nm: Increase depth from 12 to 14 from step 8

Test 1100 times, no matter black or white,
new player pk old player, result is 40% : 18~21%

Speed cut down to 67%.
self play 3000 times: win rate is 25% : 28% : 47%
self play move list is not changed.

src/mills.cpp

@@ -458,11 +458,11 @@ Depth getSearchDepth(const Position *pos)
 
     const Depth placingDepthTable_9[] = {
          +1, 7,  +7,  10,     /* 0 ~ 3 */
-        +10, 12, +12, 12,     /* 4 ~ 7 */
-        +12, 13, +13, 13,     /* 8 ~ 11 */
-        +13, 13, +13, 13,     /* 12 ~ 15 */
-        +13, 13, +13,         /* 16 ~ 18 */
-        +13                   /* 19 */
+        +10, 12, +12, 14,     /* 4 ~ 7 */
+        +14, 14, +14, 14,     /* 8 ~ 11 */
+        +14, 14, +14, 14,     /* 12 ~ 15 */
+        +14, 14, +14,         /* 16 ~ 18 */
+        +14                   /* 19 */
     };
 
     const Depth movingDepthTable[] = {