report errors

Modify CheckErr and StopOnErrErr to report the error if there aren't any
other messages.

utils/utils.go

@@ -8,17 +8,25 @@ import (
 
 func CheckErr(err error, s ...string) {
 	if err != nil {
+		if len(s) == 0 {
+			jww.CRITICAL.Println(err)
+		} else {
 			for _, message := range s {
 				jww.ERROR.Println(message)
 			}
 		}
 	}
+}
 
 func StopOnErr(err error, s ...string) {
 	if err != nil {
+		if len(s) == 0 {
+			jww.CRITICAL.Println(err)
+		} else {
 			for _, message := range s {
 				jww.CRITICAL.Println(message)
 			}
+		}
 		os.Exit(-1)
 	}
 }