Fix query creation via explorer; Extract header names to constants

api/handlers/offers.go

@@ -4,10 +4,11 @@ import (
 	"net/http"
 
 	"github.com/gin-gonic/gin"
+	"github.com/pikami/cosmium/api/headers"
 )
 
 func GetOffers(c *gin.Context) {
-	c.Header("x-ms-item-count", "0")
+	c.Header(headers.ItemCount, "0")
 	c.IndentedJSON(http.StatusOK, gin.H{
 		"_rid":   "",
 		"_count": 0,