patch 8.2.1558: signs test fails

Problem:    Signs test fails.
Solution:   Add missing change to sign.c.
diff --git a/src/version.c b/src/version.c
index 214ee2a..411a889 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1558,
+/**/
     1557,
 /**/
     1556,