patch 9.1.1320: filetype: alsoft config files are not recognized

Problem:  filetype: alsoft config files are not recognized
Solution: detect alsoft config files as dosini filetype
          (David Mandelberg)

References:
* code with paths to config: ReadALConfig() in
  https://github.com/kcat/openal-soft/blob/master/alc/alconfig.cpp
* example config:
  https://github.com/kcat/openal-soft/blob/master/alsoftrc.sample

closes: #17140

Signed-off-by: David Mandelberg <david@mandelberg.org>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1320,
 /**/
     1319,
 /**/