Rename getCurrentUser to getUser

It is never ambiguous to say "User" instead of "CurrentUser". Save
some typing.

Change-Id: I03a051f1fd3758ba63749cded20a7c135b6cf58a

gerrit-server/src/main/java/com/google/gerrit/server/change/ChangeResource.java

@@ -91,7 +91,7 @@ public class ChangeResource implements RestResource, HasETag {
 
   @Override
   public String getETag() {
-    CurrentUser user = control.getCurrentUser();
+    CurrentUser user = control.getUser();
     Hasher h = Hashing.md5().newHasher()
         .putBoolean(user.getStarredChanges().contains(getChange().getId()));
     prepareETag(h, user);