protob: rename decred_expiry to expiry (so we can use this field for Zcash too)

protob/messages.proto

@@ -655,7 +655,7 @@ message SignTx {
 	optional string coin_name = 3 [default='Bitcoin'];	// coin to use
 	optional uint32 version = 4 [default=1];		// transaction version
 	optional uint32 lock_time = 5 [default=0];		// transaction lock_time
-	optional uint32 decred_expiry = 6;			// only for Decred
+	optional uint32 expiry = 6;				// only for Decred and Zcash
 	optional bool overwintered = 7;				// only for Zcash
 }
 
@@ -675,7 +675,7 @@ message SimpleSignTx {
 	optional string coin_name = 4 [default='Bitcoin'];	// coin to use
 	optional uint32 version = 5 [default=1];		// transaction version
 	optional uint32 lock_time = 6 [default=0];		// transaction lock_time
-	optional uint32 decred_expiry = 7;			// only for Decred
+	optional uint32 expiry = 7;				// only for Decred and Zcash
 	optional bool overwintered = 8;				// only for Zcash
 }
 

protob/types.proto

@@ -226,9 +226,9 @@ message TransactionType {
 	optional uint32 lock_time = 4;
 	optional uint32 inputs_cnt = 6;
 	optional uint32 outputs_cnt = 7;
-	optional bytes extra_data = 8;
-	optional uint32 extra_data_len = 9;
-	optional uint32 decred_expiry = 10;		// only for Decred
+	optional bytes extra_data = 8;			// only for Zcash
+	optional uint32 extra_data_len = 9;		// only for Zcash
+	optional uint32 expiry = 10;			// only for Decred and Zcash
 	optional bool overwintered = 11;		// only for Zcash
 }