[gimp] libgimp: fix gimp_procedure_config_get_values().

[Jehan <jehanp src gnome org>]

commit 0734ac2aec350270dac53f3a4eef0e4ecb74c184
Author: Jehan <jehan girinstud io>
Date:   Fri Feb 11 17:42:39 2022 +0100

    libgimp: fix gimp_procedure_config_get_values().
    
    The config object has one additional property per construction, which is
    the "procedure" property.

 libgimp/gimpprocedureconfig.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/libgimp/gimpprocedureconfig.c b/libgimp/gimpprocedureconfig.c
index 3dbd8cbea8..d8235b785b 100644
--- a/libgimp/gimpprocedureconfig.c
+++ b/libgimp/gimpprocedureconfig.c
@@ -294,12 +294,13 @@ gimp_procedure_config_get_values (GimpProcedureConfig  *config,
   gimp_procedure_get_aux_arguments (config->priv->procedure, &n_aux_args);
   n_values = gimp_value_array_length (values);
 
-  g_return_if_fail (n_pspecs == n_values + n_aux_args);
+  /* The config will have 1 additional property: "procedure". */
+  g_return_if_fail (n_pspecs == n_values + n_aux_args + 1);
 
-  for (i = 0; i < n_values; i++)
+  for (i = 1; i < n_pspecs; i++)
     {
       GParamSpec *pspec = pspecs[i];
-      GValue     *value = gimp_value_array_index (values, i);
+      GValue     *value = gimp_value_array_index (values, i - 1);
 
       g_object_get_property (G_OBJECT (config), pspec->name, value);
     }