[FAB-2359] Fix Broken Master

https://jira.hyperledger.org/browse/FAB-2359

The introduction of the TxID checks on configuration transactions has
broken master.  This should be addressed more directly, but it is
causing all CI to fail.  This makes the checks only apply to endorser
transactions.

Change-Id: I1c6c7536f83e42f0281d18f8d7b147dcb243175a
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

core/common/validation/msgvalidation.go

@@ -371,20 +371,20 @@ func ValidateTransaction(e *common.Envelope) (*common.Payload, error) {
 
 	// TODO: ensure that creator can transact with us (some ACLs?) which set of APIs is supposed to give us this info?
 
-	// Verify that the transaction ID has been computed properly.
-	// This check is needed to ensure that the lookup into the ledger
-	// for the same TxID catches duplicates.
-	err = utils.CheckProposalTxID(
-		payload.Header.ChannelHeader.TxId,
-		payload.Header.SignatureHeader.Nonce,
-		payload.Header.SignatureHeader.Creator)
-	if err != nil {
-		return nil, err
-	}
-
 	// continue the validation in a way that depends on the type specified in the header
 	switch common.HeaderType(payload.Header.ChannelHeader.Type) {
 	case common.HeaderType_ENDORSER_TRANSACTION:
+		// Verify that the transaction ID has been computed properly.
+		// This check is needed to ensure that the lookup into the ledger
+		// for the same TxID catches duplicates.
+		err = utils.CheckProposalTxID(
+			payload.Header.ChannelHeader.TxId,
+			payload.Header.SignatureHeader.Nonce,
+			payload.Header.SignatureHeader.Creator)
+		if err != nil {
+			return nil, err
+		}
+
 		err = validateEndorserTransaction(payload.Data, payload.Header)
 		putilsLogger.Infof("ValidateTransactionEnvelope returns err %s", err)
 		return payload, err