patch 8.1.1190: has('vimscript-3') does not work

Problem:    has('vimscript-3') does not work.
Solution:   Add "vimscript-3" to the list of features.
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 7368ba2..a4d6ebf 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -6624,6 +6624,7 @@
 #endif
 	"vimscript-1",
 	"vimscript-2",
+	"vimscript-3",
 	"virtualedit",
 	"visual",
 	"visualextra",