[calls] flatpak: Don't build manpage

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit 8cb6c3e5a9517ad202c8673e1332955624a398e9
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Tue May 31 20:21:26 2022 +0200

    flatpak: Don't build manpage

 org.gnome.Calls.json | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/org.gnome.Calls.json b/org.gnome.Calls.json
index e9c7abd6..b703a244 100644
--- a/org.gnome.Calls.json
+++ b/org.gnome.Calls.json
@@ -312,6 +312,9 @@
             "name" : "calls",
             "builddir" : "true",
             "buildsystem" : "meson",
+            "config-opts" : [
+                "-Dmanpages=false"
+            ],
             "sources" : [
                 {
                     "type" : "git",