Rollup merge of rust-lang#27156 - AlisdairO:diagnostics253, r=Manishearth

This is a resubmission of my previous git failure - apologies.  Just fixing up a wording error that was discovered in E0253 after the r.

r? @Manishearth

Author: steveklabnik

src/librustc_resolve/diagnostics.rs

@@ -106,8 +106,7 @@ mod foo {
 use foo::MyTrait::do_something;
 ```
 
-In general, it's not legal to directly import methods belonging to a
-trait or concrete type.
+It's illegal to directly import methods belonging to a trait or concrete type.
 "##,
 
 E0255: r##"