[gimp] libgimp: add correct annotation for gimp_main().

[Jehan <jehanp src gnome org>]

commit c260b4d50df543c3f1c5b8ae494cb814b91ad9b4
Author: Jehan <jehan girinstud io>
Date:   Thu Jul 25 11:02:53 2019 +0200

    libgimp: add correct annotation for gimp_main().
    
    With GObject introspection, this allows to properly use this function,
    otherwise it sees the argv argument as a string (and not an array of
    string), which cannot be used properly.
    For instance, with Python binding, you can just call it like this:
    
    > Gimp.main (info, sys.argv)

 libgimp/gimp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/libgimp/gimp.c b/libgimp/gimp.c
index eda2a2502e..375f405706 100644
--- a/libgimp/gimp.c
+++ b/libgimp/gimp.c
@@ -260,7 +260,7 @@ static gchar             *pdb_error_message  = NULL;
  * gimp_main:
  * @info: the PLUG_IN_INFO structure
  * @argc: the number of arguments
- * @argv: the arguments
+ * @argv: (array length=argc): the arguments
  *
  * The main procedure that must be called with the PLUG_IN_INFO structure
  * and the 'argc' and 'argv' that are passed to "main".