patch 8.1.1899: sign_place() does not work as documented

Problem:    sign_place() does not work as documented.
Solution:   Make accept line numbers like line(). (Yegappan Lakshmanan,
            closes #4848)

src/version.c

@@ -765,6 +765,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1899,
 /**/
     1898,
 /**/