patch 8.0.1249: no error when WaitFor() gets an invalid wrong expression

Problem:    No error when WaitFor() gets an invalid wrong expression.
Solution:   Do not ignore errors in evaluationg the expression.  Fix places
            where the expression was wrong.
diff --git a/src/version.c b/src/version.c
index 3504ff6..56e2910 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1249,
+/**/
     1248,
 /**/
     1247,