Add .assignee to gr-change-list-styles

Change-Id: Id874df2d06a8264b770e3e364634bd28ec821467

polygerrit-ui/app/styles/gr-change-list-styles.html

diff --git a/polygerrit-ui/app/styles/gr-change-list-styles.html b/polygerrit-ui/app/styles/gr-change-list-styles.html
index 00ea613..c479c1a 100644
--- a/polygerrit-ui/app/styles/gr-change-list-styles.html
+++ b/polygerrit-ui/app/styles/gr-change-list-styles.html
@@ -45,6 +45,7 @@
       .label,
       .number,
       .owner,
+      .assignee,
       .updated,
       .size,
       .status,