vim-patch:7.4.1533 #5320

Problem:    Using feedkeys() with an empty string disregards 'x' option.
Solution:   Make 'x' work with an empty string. (Thinca)

When integrating the patch to nvim, used same logic but different code
based on nvim codebase. New test passed.

74c5bbf134

src/nvim/version.c

@@ -745,7 +745,7 @@ static int included_patches[] = {
   // 1536 NA
   // 1535,
   // 1534 NA
-  // 1533,
+  1533,
   // 1532 NA
   // 1531 NA
   // 1530 NA