patch 8.2.5117: crash when calling a Lua callback from a :def function

Problem:    Crash when calling a Lua callback from a :def function. (Bohdan
            Makohin)
Solution:   Handle FC_CFUNC in call_user_func_check(). (closes #10587)

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    5117,
 /**/
     5116,
 /**/