Fix "#dashboard,accountId" links to work again

I broke these when I rewrote the Link class to use startsWith instead
of regex pattern matching.

Signed-off-by: Shawn O. Pearce <sop@google.com>

appjar/src/main/java/com/google/gerrit/client/Link.java

@@ -121,7 +121,7 @@ public class Link implements HistoryListener {
       return new ChangeScreen(Change.Id.parse(skip(p, token)));
 
     p = "dashboard,";
-    if (token.matches(p))
+    if (token.startsWith(p))
       return new AccountDashboardScreen(Account.Id.parse(skip(p, token)));
 
     return null;