patch 8.1.0819: a failed assert with a long string is hard to read

Problem:    A failed assert with a long string is hard to read.
Solution:   Shorten the assert message.

src/version.c

@@ -787,6 +787,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    819,
 /**/
     818,
 /**/