[gtk-vnc] meson: Find python explicitly to honor downstream python choice

[Daniel P. Berrange <dberrange src gnome org>]

commit 4609ad35b6dc11f016ac3a50158eeef7f19d9889
Author: Mart Raudsepp <leio gentoo org>
Date:   Sun Apr 5 00:05:49 2020 +0300

    meson: Find python explicitly to honor downstream python choice

 src/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/meson.build b/src/meson.build
index 5306fb9..247c597 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -319,7 +319,7 @@ gtk_vnc_sources = gtk_vnc_gir_sources + gvnc_marshal + [
   'vncdisplaykeymap.c',
 ]
 
-python = import('python').find_installation()
+python = import('python').find_installation('python3')
 keymaps = [
   'xorgevdev',
   'xorgkbd',