params: fix timestamp display in fork banner (ethereum#26553)

Author: fjl

params/config.go

@@ -591,13 +591,13 @@ func (c *ChainConfig) Description() string {
 	// Create a list of forks post-merge
 	banner += "Post-Merge hard forks (timestamp based):\n"
 	if c.ShanghaiTime != nil {
-		banner += fmt.Sprintf(" - Shanghai:                    @%-10v (https://github.com/ethereum/execution-specs/blob/master/network-upgrades/mainnet-upgrades/shanghai.md)\n", c.ShanghaiTime)
+		banner += fmt.Sprintf(" - Shanghai:                    @%-10v (https://github.com/ethereum/execution-specs/blob/master/network-upgrades/mainnet-upgrades/shanghai.md)\n", *c.ShanghaiTime)
 	}
 	if c.CancunTime != nil {
-		banner += fmt.Sprintf(" - Cancun:                      @%-10v\n", c.CancunTime)
+		banner += fmt.Sprintf(" - Cancun:                      @%-10v\n", *c.CancunTime)
 	}
 	if c.PragueTime != nil {
-		banner += fmt.Sprintf(" - Prague:                      @%-10v\n", c.PragueTime)
+		banner += fmt.Sprintf(" - Prague:                      @%-10v\n", *c.PragueTime)
 	}
 	return banner
 }