fix 代码错误

app/src/main/java/com/doverfuelingsolutions/issp/api/SystemApi.kt

@@ -397,11 +397,14 @@ object SystemApi {
                         return
                     }
                     // 加油员
+                    var operator = ""
                     val index1 = body.indexOf("加油员：")
-                    val index2 = body.indexOf("<", index1)
-                    val fuelGuy = body.slice((index1 + 4) until index2).trim()
+                    if (index1 > -1) {
+                        val index2 = body.indexOf("<", index1)
+                        operator = body.slice((index1 + 4) until index2).trim()
+                    }
                     it.resume(DFSResult.success(ResultPosTicketInfo(
-                        fuelGuy
+                        operator
                     )))
                 }