patch 8.1.0870: Vim doesn't use the new ConPTY support in Windows 10

Problem:    Vim doesn't use the new ConPTY support in Windows 10.
Solution:   Use ConPTY support, if available. (Nobuhiro Takasaki, closes #3794)
diff --git a/src/option.h b/src/option.h
index 90c0508..2985781 100644
--- a/src/option.h
+++ b/src/option.h
@@ -1112,6 +1112,7 @@
 #ifdef FEAT_TERMINAL
     , WV_TWK
     , WV_TWS
+    , WV_TMOD
 #endif
     , WV_CRBIND
 #ifdef FEAT_LINEBREAK