allow rustfmt to reorder imports

This wasn't a right decision in the first place, the feature flag was
broken in the last rustfmt release, and syntax highlighting of imports
is more important anyway

crates/ra_syntax/src/validation.rs

@@ -4,11 +4,10 @@ mod block;
 mod field_expr;
 
 use crate::{
-    SourceFile, SyntaxError, AstNode, SyntaxNode, TextUnit,
-    SyntaxKind::{BYTE, BYTE_STRING, STRING, CHAR},
-    ast,
     algo::visit::{visitor_ctx, VisitorCtx},
-    T,
+    ast, AstNode, SourceFile, SyntaxError,
+    SyntaxKind::{BYTE, BYTE_STRING, CHAR, STRING},
+    SyntaxNode, TextUnit, T,
 };
 
 pub(crate) use unescape::EscapeError;