vim-patch:7.4.1981 (#6192)

Problem:    No testing for Farsi code.
Solution:   Add a minimal test.  Clean up Farsi code.

ee2615af64

src/nvim/version.c

@@ -459,7 +459,7 @@ static int included_patches[] = {
   1984,
   // 1983 NA
   // 1982 NA
-  // 1981,
+  1981,
   1980,
   // 1979,
   // 1978,