Expose resetHtml in NavigationTable to all callers

This simplifies a calling pattern where a sibling class to the
subclass of NavigationTable wants to invoke resetHtml().

Change-Id: I1e5c148298ef41905df62916c44536ae8fe50ef9

gerrit-gwtui/src/main/java/com/google/gerrit/client/ui/NavigationTable.java

@@ -259,7 +259,7 @@ public abstract class NavigationTable<RowItem> extends FancyFlexTable<RowItem> {
   }
 
   @Override
-  protected void resetHtml(SafeHtml body) {
+  public void resetHtml(SafeHtml body) {
     currentRow = -1;
     super.resetHtml(body);
   }