don't make gradebook_history styles global

there is no need to as they only apply to the
gradebook history page

test plan:
* /courses/x/gradebook/history and make sure
  everything is still styled right

Change-Id: I69d194090ab5c7afa1fd597aefa78d7189f81889
Reviewed-on: https://gerrit.instructure.com/9873
Tested-by: Hudson <hudson@instructure.com>
Reviewed-by: Joe Tanner <joe@instructure.com>

app/views/gradebooks/history.html.erb

@@ -1,5 +1,5 @@
 <% content_for :page_title do %><%= join_title t(:page_title, "Gradebook History"), @context.name %><% end %>
-
+<% jammit_css :gradebook_history %>
 <% content_for :auto_discovery do %>
   <% if @context_enrollment %>
     <%= auto_discovery_link_tag(:atom, feeds_gradebook_url(@context_enrollment.feed_code), {:title => t('titles.feed', "Course Gradebook Atom Feed")}) %>

config/assets.yml

@@ -123,7 +123,6 @@ stylesheets:
     - public/stylesheets/compiled/g_util_ui_listview.css
     - public/stylesheets/compiled/g_assignments.css
     - public/stylesheets/compiled/g_content_imports.css
-    - public/stylesheets/compiled/g_gradebook_history.css
     - public/stylesheets/compiled/g_context_inbox.css
     - public/stylesheets/compiled/g_groups.css
     - public/stylesheets/compiled/g_media_comments.css
@@ -170,6 +169,8 @@ stylesheets:
     - public/stylesheets/compiled/full_files.css
   datagrid:
     - public/stylesheets/compiled/datagrid.css
+  gradebook_history:
+    - public/stylesheets/compiled/gradebook_history.css
   gradebooks:
     - public/stylesheets/compiled/gradebooks.css
     - public/stylesheets/compiled/message_students.css