[libpeas] build: fix typo in get_option()

[Christian Hergert <chergert src gnome org>]

commit 78fbb515b3b60b1891c13773181257492824fcca
Author: Christian Hergert <chergert redhat com>
Date:   Mon Aug 5 16:00:47 2019 -0700

    build: fix typo in get_option()

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 17b9749..1869864 100644
--- a/meson.build
+++ b/meson.build
@@ -171,7 +171,7 @@ if build_python2_loader and not python2_found
   build_python2_loader = false
 endif
 
-build_python3_loader = get_option('python2')
+build_python3_loader = get_option('python3')
 python3_found = python3_dep.found() and pygobject_dep.found()
 if build_python3_loader and not python3_found
   build_python3_loader = false