patch 9.1.1506: tests: missing cleanup in Test_search_cmdline_incsearch_highlight()

Problem:  tests: missing cleanup test_override('char_avail', 0) in
          Test_search_cmdline_incsearch_highlight().
Solution: Add the missing cleanup (zeertzjq).

closes: #17655

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 48d9a44..d5a882d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -720,6 +720,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1506,
+/**/
     1505,
 /**/
     1504,