patch 7.4.2088

Problem:    Keymap test fails with normal features.
Solution:   Bail out if the keymap feature is not supported.

src/version.c

@@ -758,6 +758,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2088,
 /**/
     2087,
 /**/