remove trailing whitespace

Author: coke

doc/Type/Range.pod6

@@ -185,7 +185,7 @@ by not actually generating the list if it is not necessary.
 
     multi method sum() returns Numeric:D
 
-Returns the sum of all elements in the Range. Throws X::Str::Numeric if an element can not be coerced into Numeric.    
+Returns the sum of all elements in the Range. Throws X::Str::Numeric if an element can not be coerced into Numeric.
 
     (1..10).sum #55