routing: add time_pref parameter to queryroutes and sendpayment

lnrpc/lightning.swagger.json

@@ -1380,6 +1380,14 @@
               ]
             },
             "collectionFormat": "multi"
+          },
+          {
+            "name": "time_pref",
+            "description": "The time preference for this payment. Set to -1 to optimize for fees\nonly, to 1 to optimize for reliability only or a value inbetween for a mix.",
+            "in": "query",
+            "required": false,
+            "type": "number",
+            "format": "double"
           }
         ],
         "tags": [