patch 9.1.0307: filetype: texdoc config files is not recognized

Problem:  filetype: texdoc config files is not recognized
Solution: Detect 'texdoc.cnf' as conf filetype
          (Wu, Zhenyu)

See: https://github.com/TeX-Live/texdoc/blob/master/texdoc.cnf

closes: #14507

Signed-off-by: Wu, Zhenyu <wuzhenyu@ustc.edu>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index a7a9664..8712523 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    307,
+/**/
     306,
 /**/
     305,