remove matrix_riot_web_change_default_theme and provide sane default

roles/matrix-riot-web/defaults/main.yml

@@ -76,11 +76,12 @@ matrix_riot_web_enable_presence_by_hs_url: ~
 matrix_riot_web_themes_enabled: false
 matrix_riot_web_themes_repository_url: https://github.com/aaronraimist/riot-web-themes
 
+# Controls the default riot-web theme
+matrix_riot_web_default_theme: 'light'
+
 # Controls the `settingsDefault.custom_themes` setting of the riot-web configuration.
 # You can use this setting to define custom themes.
-matrix_riot_web_change_default_theme: false
-matrix_riot_web_default_theme: ""
-
+#
 # Also, look at `matrix_riot_web_themes_enabled` for a way to pull in a bunch of custom themes automatically.
 # If you define your own themes here and set `matrix_riot_web_themes_enabled: true`, your themes will be preserved as well.
 #

roles/matrix-riot-web/templates/config.json.j2

@@ -11,9 +11,7 @@
 	"settingDefaults": {
 		"custom_themes": {{ matrix_riot_web_settingDefaults_custom_themes|to_json }}
 	},
-	{% if matrix_riot_web_change_default_theme %}
-		"default_theme": {{ matrix_riot_web_default_theme|string|to_json }},
-	{% endif %}
+	"default_theme": {{ matrix_riot_web_default_theme|string|to_json }},
 	"permalinkPrefix": {{ matrix_riot_web_permalinkPrefix|string|to_json }},
 	"disable_custom_urls": {{ matrix_riot_web_disable_custom_urls|to_json }},
 	"disable_guests": {{ matrix_riot_web_disable_guests|to_json }},