[evolution] Correct a variable name

[Milan Crha <mcrha src gnome org>]

commit 8e1bc6a68f799b39cef5fdceff89ad807010b102
Author: Milan Crha <mcrha redhat com>
Date:   Mon Aug 15 14:30:14 2016 +0200

    Correct a variable name

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 9ccfcfe..6f694a6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -287,7 +287,7 @@ PKG_CHECK_MODULES([GNOME_PLATFORM],
         libxml-2.0 >= libxml_minimum_version
         shared-mime-info >= shared_mime_info_minimum_version
         gsettings-desktop-schemas >= gsettings_desktop_schemas_minimum_version
-        webkit2gtk-4.0 >= webkitgtk_minimum_version
+        webkit2gtk-4.0 >= webkit2gtk_minimum_version
         $GIO_UNIX_REQUIREMENT])
 
 GNOME_DESKTOP_DEPENDENCY=""