[glibmm/glibmm-2-52] ActionMap: Revert accidental changes to Slot decls

[Daniel Boles <dboles src gnome org>]

commit f81107735d04569d6a9bd1bf473980f3ef1f1e01
Author: Daniel Boles <dboles src gmail com>
Date:   Wed May 31 20:34:43 2017 +0100

    ActionMap: Revert accidental changes to Slot decls
    
    I cherry-picked a commit from master that should only have updated
    documentation, but because the way of declaring slots has been changed
    in libsigc++, it ended up changing them here too. That was unintentional

 gio/src/actionmap.hg |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gio/src/actionmap.hg b/gio/src/actionmap.hg
index 4194cdb..f7e097b 100644
--- a/gio/src/actionmap.hg
+++ b/gio/src/actionmap.hg
@@ -74,7 +74,7 @@ public:
    * For instance,
    * void on_slot_activated();
    */
-  using ActivateSlot = sigc::slot<void()>;
+  using ActivateSlot = sigc::slot<void>;
 
   /** A convenience method for creating a SimpleAction instance
    * and adding it to the ActionMap.
@@ -93,7 +93,7 @@ public:
    * For instance,
    * void on_slot_activated(const Glib::VariantBase& parameter);
    */
-  using ActivateWithParameterSlot = sigc::slot<void(const Glib::VariantBase&)>;
+  using ActivateWithParameterSlot = sigc::slot<void, const Glib::VariantBase&>;
 
 _DEPRECATE_IFDEF_START
   /** A convenience method for creating a SimpleAction instance