lnrpc: fix description of tx_index to be correct[skip ci]

lnrpc/chainrpc/chainnotifier.pb.go

@@ -125,7 +125,7 @@ type ConfDetails struct {
 	// The height of the block in which the confirmed transaction was included
 	// in.
 	BlockHeight uint32 `protobuf:"varint,3,opt,name=block_height,json=blockHeight,proto3" json:"block_height,omitempty"`
-	// The index of the confirmed transaction within the transaction.
+	// The index of the confirmed transaction within the block.
 	TxIndex uint32 `protobuf:"varint,4,opt,name=tx_index,json=txIndex,proto3" json:"tx_index,omitempty"`
 	// The raw bytes of the block that mined the transaction. Only included if
 	// include_block was set in the request.

lnrpc/chainrpc/chainnotifier.proto

@@ -91,7 +91,7 @@ message ConfDetails {
     // in.
     uint32 block_height = 3;
 
-    // The index of the confirmed transaction within the transaction.
+    // The index of the confirmed transaction within the block.
     uint32 tx_index = 4;
 
     /*

lnrpc/chainrpc/chainnotifier.swagger.json

@@ -183,7 +183,7 @@
         "tx_index": {
           "type": "integer",
           "format": "int64",
-          "description": "The index of the confirmed transaction within the transaction."
+          "description": "The index of the confirmed transaction within the block."
         },
         "raw_block": {
           "type": "string",