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)
diff --git a/src/version.c b/src/version.c
index 0689e03..f91f07b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -766,6 +766,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1899,
+/**/
     1898,
 /**/
     1897,