Fix forging L1Batch too early

When scheduling an L1Batch, make sure the previous L1Batch has been
synchronized.  Otherwise, an L1Batch will be forged that may not contain all
the L1UserTxs that are supposed to be included.

config/config.go

@@ -54,6 +54,9 @@ type Coordinator struct {
 	// ProofServerPollInterval is the waiting interval between polling the
 	// ProofServer while waiting for a particular status
 	ProofServerPollInterval Duration `validate:"required"`
+	// ForgeRetryInterval is the waiting interval between calls forge a
+	// batch after an error
+	ForgeRetryInterval Duration `validate:"required"`
 	// SyncRetryInterval is the waiting interval between calls to the main
 	// handler of a synced block after an error
 	SyncRetryInterval Duration `validate:"required"`