fixed: when RelatedSel have multi string/relation, it only get last string

@@ -115,14 +115,13 @@ func (o querySet) OrderBy(exprs ...string) QuerySeter {
 // set relation model to query together.
 // set relation model to query together.
 // it will query relation models and assign to parent model.
 // it will query relation models and assign to parent model.
 func (o querySet) RelatedSel(params ...interface{}) QuerySeter {
 func (o querySet) RelatedSel(params ...interface{}) QuerySeter {
-	var related []string
     if len(params) == 0 {
     if len(params) == 0 {
         o.relDepth = DefaultRelsDepth
         o.relDepth = DefaultRelsDepth
     } else {
     } else {
         for _, p := range params {
         for _, p := range params {
             switch val := p.(type) {
             switch val := p.(type) {
             case string:
             case string:
-				related = append(o.related, val)
+                o.related = append(o.related, val)
             case int:
             case int:
                 o.relDepth = val
                 o.relDepth = val
             default:
             default:
@@ -130,7 +129,6 @@ func (o querySet) RelatedSel(params ...interface{}) QuerySeter {
             }
             }
         }
         }
     }
     }
-	o.related = related
     return &o
     return &o
 }
 }