[gspell] build: require Enchant >= 2.2.12

[Sébastien Wilmet <swilmet src gnome org>]

commit 65e93eb93cfa9301f8ab723a03e0274ef58ced2f
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Fri Oct 23 19:44:53 2020 +0200

    build: require Enchant >= 2.2.12
    
    Enchant 2.2.12 fixes this issue with the Voikko backend:
    https://gitlab.gnome.org/GNOME/gspell/-/issues/10

 README       | 2 +-
 configure.ac | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/README b/README
index f14c9ce..90f88af 100644
--- a/README
+++ b/README
@@ -26,7 +26,7 @@ Dependencies
 
 * GLib >= 2.44
 * GTK >= 3.20
-* Enchant >= 2.1.3
+* Enchant >= 2.2.12
 * ICU - http://site.icu-project.org/
 
 Notes for packagers
diff --git a/configure.ac b/configure.ac
index 15da2b1..695a27c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -50,7 +50,7 @@ GSPELL_API_VERSION=1
 AC_SUBST(GSPELL_API_VERSION)
 
 # Dependencies
-enchant_req=2.1.3
+enchant_req=2.2.12
 glib_req=2.44
 gtk_req=3.20