Fix comments not showing after commenting

app/src/main/kotlin/com/hippo/ehviewer/client/EhEngine.kt

@@ -254,13 +254,18 @@ object EhEngine {
                 append("edit_comment", id.toString())
             }
         }
-    }.fetchUsingAsText {
-        val document = Jsoup.parse(this)
-        val elements = document.select("#chd + p")
-        if (elements.size > 0) {
-            throw EhException(elements[0].text())
+    }.execute { response ->
+        // Ktor does not handle POST redirect, we need to do it manually
+        // https://youtrack.jetbrains.com/issue/KTOR-478
+        val location = response.headers["Location"] ?: url
+        ehRequest(location, url).fetchUsingAsText {
+            val document = Jsoup.parse(this)
+            val elements = document.select("#chd + p")
+            if (elements.size > 0) {
+                throw EhException(elements[0].text())
+            }
+            GalleryDetailParser.parseComments(document)
         }
-        GalleryDetailParser.parseComments(document)
     }
 
     suspend fun modifyFavorites(gid: Long, token: String?, dstCat: Int = -1, note: String = "") {