tweak canceled message

crates/ra_db/src/lib.rs

@@ -15,7 +15,7 @@ pub type Cancelable<T> = Result<T, Canceled>;
 
 impl std::fmt::Display for Canceled {
     fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        fmt.write_str("Canceled")
+        fmt.write_str("canceled")
     }
 }
 

crates/ra_lsp_server/src/main_loop.rs

@@ -387,7 +387,7 @@ impl<'a> PoolDispatcher<'a> {
                                     RawResponse::err(
                                         id,
                                         ErrorCode::ContentModified as i32,
-                                        e.to_string(),
+                                        format!("content modified: {}", e),
                                     )
                                 } else {
                                     RawResponse::err(