patch 8.0.1770: assert functions don't return anything

Problem:    Assert functions don't return anything.
Solution:   Return non-zero when the assertion fails.
diff --git a/src/version.c b/src/version.c
index 0a36b66..a824e8d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1770,
+/**/
     1769,
 /**/
     1768,