Clean up a string

Author: robintown

locales/en/app.json

@@ -166,7 +166,7 @@
     },
     "background_blur_header": "Background",
     "background_blur_label": "Blur the background of the video",
-    "blur_not_supported_by_browser": "(Background blur is not supported by this device)",
+    "blur_not_supported_by_browser": "(Background blur is not supported by this device.)",
     "developer_tab_title": "Developer",
     "devices": {
       "camera": "Camera",