patch 8.1.1697: cannot build with MSVC

Problem:    Cannto build with MSVC.
Solution:   Remove the backslashes after the @<< mechanism.

src/version.c

@@ -777,6 +777,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1697,
 /**/
     1696,
 /**/