return error message when target is not ok

ogame.go

@@ -2828,6 +2828,10 @@ type CheckTargetResponse struct {
 		Type     int    `json:"type"`
 		Name     string `json:"name"`
 	} `json:"targetPlanet"`
+	Errors []struct {
+		Message string `json:"message"`
+		Error   int    `json:"error"`
+	} `json:"errors"`
 	TargetOk   bool          `json:"targetOk"`
 	Components []interface{} `json:"components"`
 }
@@ -2973,6 +2977,9 @@ func (b *OGame) sendFleetV7(celestialID CelestialID, ships []Quantifiable, speed
 	}
 
 	if !checkRes.TargetOk {
+		if len(checkRes.Errors) > 0 {
+			return Fleet{}, errors.New(checkRes.Errors[0].Message)
+		}
 		return Fleet{}, errors.New("target is not ok")
 	}