minor fix: remove extra space in a newer string

Remove an extra space in a recently added string for ankidroid#18071

Author: snowtimeglass

AnkiDroid/src/main/res/values/02-strings.xml

@@ -176,7 +176,7 @@
     <!-- Deckpicker Background -->
     <string name="background_image_title" maxLength="41">Background</string>
     <string name="choose_an_image" maxLength="41">Select image</string>
-    <string name="remove_wallpaper_image" maxLength="41"> Remove background</string>
+    <string name="remove_wallpaper_image" maxLength="41">Remove background</string>
     <string name="remove_background_image">Remove background?</string>
     <!-- Card Template Browser Appearance -->
     <string name="restore_default" maxLength="28">Restore Default</string>