patch 7.4.2304

Problem:    In a timer callback the timer itself can't be found or stopped.
            (Thinca)
Solution:   Do not remove the timer from the list, remember whether it was
            freed.

src/version.c

@@ -763,6 +763,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2304,
 /**/
     2303,
 /**/