fix: xsel copy should not freeze the editor

If using --nodetach, xsel would end up continually running in the
foreground, so the command execution would never finish.

Fixes #630

helix-view/src/clipboard.rs

@@ -84,7 +84,7 @@ pub fn get_clipboard_provider() -> Box<dyn ClipboardProvider> {
         // FIXME: check performance of is_exit_success
         command_provider! {
             paste => "xsel", "-o", "-b";
-            copy => "xsel", "--nodetach", "-i", "-b";
+            copy => "xsel", "-i", "-b";
             primary_paste => "xsel", "-o";
             primary_copy => "xsel", "-i";
         }