patch 8.2.3762: if quickfix buffer is wiped out getqflist() still returns it

Problem:    If the quickfix buffer is wiped out getqflist() still returns its
            number.
Solution:   Use zero if the buffer is no longer present. (Yegappan Lakshmanan,
            closes #9306)

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3762,
 /**/
     3761,
 /**/