Fix ProxyProtocol double destructor call in HttpTransact::State (#12724)

Removes explicit destructor call for pp_info member in HttpTransact::State::destroy().

The explicit destructor call was causing undefined behavior as the
ProxyProtocol member will be automatically destroyed when the State object is
destroyed. This resulted in a double-free detected by GCC 15 in Fedora 42 builds.

The member variable pp_info is a regular class member, not allocated with
placement new, so it will be properly destroyed automatically when the State
object is destroyed or when the destructor runs.

Author: bryancall

include/proxy/http/HttpTransact.h

@@ -889,8 +889,6 @@ class HttpTransact
       ranges      = nullptr;
       range_setup = RangeSetup_t::NONE;
 
-      // This avoids a potential leak since sometimes this class is not destructed (ClassAllocated via HttpSM)
-      pp_info.~ProxyProtocol();
       return;
     }