project: Add configurable gettext domain

The gettext domain is hardcoded in the gschema file. It has been
changed so its now configurable and its possible to change it
via build files.

data/meson.build

@@ -22,9 +22,17 @@ install_data(
 )
 
 # GSettings schema
-install_data(
-  'org.gnome.calendar.gschema.xml',
-  install_dir: calendar_schemadir
+schema_conf = configuration_data()
+schema_conf.set('GETTEXT_PACKAGE', meson.project_name())
+
+schema = 'org.gnome.calendar.gschema.xml'
+
+configure_file(
+  input: schema + '.in',
+  output: schema,
+  install: true,
+  install_dir: calendar_schemadir,
+  configuration: schema_conf
 )
 
 # DBus service files

data/org.gnome.calendar.gschema.xml.in

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<schemalist gettext-domain="gnome-calendar">
+<schemalist gettext-domain="@GETTEXT_PACKAGE@">
     <schema id="org.gnome.calendar" path="/org/gnome/calendar/">
         <key name="window-maximized" type="b">
             <default>true</default>

po/POTFILES.in

@@ -2,7 +2,7 @@
 # Please keep this file sorted alphabetically.
 data/appdata/org.gnome.Calendar.appdata.xml.in
 data/org.gnome.Calendar.desktop.in
-data/org.gnome.calendar.gschema.xml
+data/org.gnome.calendar.gschema.xml.in
 data/ui/alarm-row.ui
 data/ui/edit-dialog.ui
 data/ui/help-overlay.ui