vim-patch:7.4.1547 #5326

Problem:    Getting a cterm highlight attribute that is not set results in the
            string "-1".
Solution:   Return an empty string. (Taro Muraoka)

385111bd86

src/nvim/version.c

@@ -730,7 +730,7 @@ static int included_patches[] = {
   1550,
   // 1549,
   1548,
-  // 1547,
+  1547,
   1546,
   // 1545 NA
   // 1544 NA