Reset font weight for label columns

A recent change modified font weights, but label scores (especially
icons) look strange when bolded.

Change-Id: I1babdbb34d15eb53a09899a0e33afb7903d574f9
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.html b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.html
index b8119b7..9a3fc03 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.html
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.html
@@ -114,6 +114,9 @@
       .placeholder {
         color: var(--deemphasized-text-color);
       }
+      .cell.label {
+        font-weight: normal;
+      }
       @media only screen and (max-width: 50em) {
         :host {
           display: flex;