Added a missing space to the description of the `cut` filter.

docs/ref/templates/builtins.txt

@@ -1184,7 +1184,7 @@ Removes all values of arg from the given string.
 
 For example::
 
-    {{ value|cut:" "}}
+    {{ value|cut:" " }}
 
 If ``value`` is ``"String with spaces"``, the output will be
 ``"Stringwithspaces"``.