patch 8.0.1723: using one item array size declaration is misleading

Problem:    Using one item array size declaration is misleading.
Solution:   Instead of using "[1]" and actually using a larger array, use
            "[]".  This is to verify that this C99 feature works for all
            compilers.

src/version.c

@@ -762,6 +762,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1723,
 /**/
     1722,
 /**/