lnrpc: add payment cltv limit

lnrpc/rpc.proto

@@ -790,7 +790,14 @@ message SendRequest {
     any channel may be used.
     */
     uint64 outgoing_chan_id = 9;
+
+    /** 
+    An optional maximum total time lock for the route. If zero, there is no
+    maximum enforced.
+    */
+    uint32 cltv_limit = 10;
 }
+
 message SendResponse {
     string payment_error = 1 [json_name = "payment_error"];
     bytes payment_preimage = 2 [json_name = "payment_preimage"];

lnrpc/rpc.swagger.json

@@ -2977,6 +2977,11 @@
           "type": "string",
           "format": "uint64",
           "description": "*\nThe channel id of the channel that must be taken to the first hop. If zero,\nany channel may be used."
+        },
+        "cltv_limit": {
+          "type": "integer",
+          "format": "int64",
+          "description": "* \nAn optional maximum total time lock for the route. If zero, there is no\nmaximum enforced."
         }
       }
     },