patch 7.4.2068

Problem:    Not all arguments of trunc_string() are tested.  Memory access
            error when running the message tests.
Solution:   Add another test case. (Yegappan Lakshmanan)  Make it easy to run
            unittests with valgrind.  Fix the access error.

src/version.c

@@ -758,6 +758,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2068,
 /**/
     2067,
 /**/