patch 9.1.1503: filetype: haxe files are not recognized

Problem:  filetype: haxe files are not recognized
Solution: detect *.hx files as haxe filetype (0xadk)

References:
- https://haxe.org/
- https://code.haxe.org/category/beginner/hello-world.html

closes: #17644

Signed-off-by: 0xadk <0xadk@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/version.c

@@ -719,6 +719,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1503,
 /**/
     1502,
 /**/