patch 9.1.1173: filetype: ABNF files are not detected

Problem:  filetype: ABNF files are not detected
Solution: detect '.abnf' file as abnf filetype and
          include an abnf syntax plugin (A4-Tacks).

References:
- RFC5234
- RFC7405

closes: #16802

Signed-off-by: A4-Tacks <wdsjxhno1001@163.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index cfb661e..8b42a79 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1173,
+/**/
     1172,
 /**/
     1171,