Remove message connection settings (API Change)

include/beast/http/impl/fields.ipp

@@ -662,48 +662,6 @@ content_length_impl(std::uint64_t n)
         to_static_string(n));
 }
 
-template<class Allocator>
-inline
-void
-basic_fields<Allocator>::
-connection_impl(close_t)
-{
-    auto it = find("Connection");
-    if(it == end())
-        this->insert("Connection", "close");
-    else
-        this->replace("Connection",
-            it->value().to_string() + ", close");
-}
-
-template<class Allocator>
-inline
-void
-basic_fields<Allocator>::
-connection_impl(keep_alive_t)
-{
-    auto it = find("Connection");
-    if(it == end())
-        this->insert("Connection", "keep-alive");
-    else
-        this->replace("Connection",
-            it->value().to_string() + ", keep-alive");
-}
-
-template<class Allocator>
-inline
-void
-basic_fields<Allocator>::
-connection_impl(upgrade_t)
-{
-    auto it = find("Connection");
-    if(it == end())
-        this->insert("Connection", "upgrade");
-    else
-        this->replace("Connection",
-            it->value().to_string() + ", upgrade");
-}
-
 template<class Allocator>
 inline
 void