updated for version 7.3.615

Problem:    Completion for a user command does not recognize backslash before
            a space.
Solution:   Recognize escaped characters. (Yasuhiro Matsumoto)

src/version.c

@@ -714,6 +714,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    615,
 /**/
     614,
 /**/