Background Button: Change unsupported image format notification message

src/po/nightthemeswitcher@romainvigier.fr.pot

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: nightthemeswitcher@romainvigier.fr\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2022-08-16 09:46+0200\n"
+"POT-Creation-Date: 2022-08-16 09:49+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -169,7 +169,7 @@ msgid ":"
 msgstr ""
 
 #: src/preferences/BackgroundButton.js:69
-msgid "Only JPEG, PNG, TIFF, SVG and XML files can be set as background image."
+msgid "This image format is not supported."
 msgstr ""
 
 #: src/preferences/ContributePage.js:16

src/preferences/BackgroundButton.js

@@ -66,7 +66,7 @@ var BackgroundButton = GObject.registerClass({
             } else {
                 if (this.root instanceof Adw.PreferencesWindow) {
                     this.root.add_toast(new Adw.Toast({
-                        title: _('Only JPEG, PNG, TIFF, SVG and XML files can be set as background image.'),
+                        title: _('This image format is not supported.'),
                         timeout: 10,
                     }));
                 }