Fix wrong include path in api-header template (#3062)

Change local json.hpp include path to correct value.

Update samples.

samples/server/petstore/cpp-pistache/model/Inline_object.cpp

@@ -0,0 +1,101 @@
+/**
+* OpenAPI Petstore
+* This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
+*
+* The version of the OpenAPI document: 1.0.0
+* 
+*
+* NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+* https://openapi-generator.tech
+* Do not edit the class manually.
+*/
+
+
+#include "Inline_object.h"
+
+namespace org {
+namespace openapitools {
+namespace server {
+namespace model {
+
+Inline_object::Inline_object()
+{
+    m_Name = "";
+    m_NameIsSet = false;
+    m_Status = "";
+    m_StatusIsSet = false;
+    
+}
+
+Inline_object::~Inline_object()
+{
+}
+
+void Inline_object::validate()
+{
+    // TODO: implement validation
+}
+
+void to_json(nlohmann::json& j, const Inline_object& o)
+{
+    j = nlohmann::json();
+    if(o.nameIsSet())
+        j["name"] = o.m_Name;
+    if(o.statusIsSet())
+        j["status"] = o.m_Status;
+}
+
+void from_json(const nlohmann::json& j, Inline_object& o)
+{
+    if(j.contains("name"))
+    {
+        j.at("name").get_to(o.m_Name);
+        o.m_NameIsSet = true;
+    } 
+    if(j.contains("status"))
+    {
+        j.at("status").get_to(o.m_Status);
+        o.m_StatusIsSet = true;
+    } 
+}
+
+std::string Inline_object::getName() const
+{
+    return m_Name;
+}
+void Inline_object::setName(std::string const& value)
+{
+    m_Name = value;
+    m_NameIsSet = true;
+}
+bool Inline_object::nameIsSet() const
+{
+    return m_NameIsSet;
+}
+void Inline_object::unsetName()
+{
+    m_NameIsSet = false;
+}
+std::string Inline_object::getStatus() const
+{
+    return m_Status;
+}
+void Inline_object::setStatus(std::string const& value)
+{
+    m_Status = value;
+    m_StatusIsSet = true;
+}
+bool Inline_object::statusIsSet() const
+{
+    return m_StatusIsSet;
+}
+void Inline_object::unsetStatus()
+{
+    m_StatusIsSet = false;
+}
+
+}
+}
+}
+}
+