Memory leak

(cherry picked from commit 63dccac9503049cfb6c8bf3fa72d07092d879274)

Source commit: 0072d3f0a6f6131c2921eaaa7e8701e66d588a07

source/core/PuttyIntf.cpp

@@ -749,6 +749,7 @@ void FreeKey(TPrivateKey * PrivateKey)
 {
   struct ssh2_userkey * Ssh2Key = reinterpret_cast<struct ssh2_userkey *>(PrivateKey);
   ssh_key_free(Ssh2Key->key);
+  sfree(Ssh2Key->comment);
   sfree(Ssh2Key);
 }
 //---------------------------------------------------------------------------