patch 7.4.1846

Problem:    Ubsan detects a multiplication overflow.
Solution:   Don't use orig_mouse_time when it's zero. (Dominique Pelle)

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1846,
 /**/
     1845,
 /**/