update http4k to fix apache server problem (#3665)

frameworks/Kotlin/http4k/.gitignore

@@ -0,0 +1,4 @@
+build
+out
+docker
+.idea

frameworks/Kotlin/http4k/build.gradle

@@ -1,6 +1,6 @@
 buildscript {
     ext.kotlin_version = "1.2.31"
-    ext.http4k_version = "3.17.0"
+    ext.http4k_version = "3.26.5"
 
     repositories {
         mavenCentral()