pyuno_loader::CreateInstance: delete the initial PyThreadState

Don't see how it could be used again, it appears to be leaked
and causes the assertion in PyThreadState_Swap to fire.

Change-Id: Id6bbb4363928e4fdd8bda1905f6e1f9931dba74c
Reviewed-on: https://gerrit.libreoffice.org/3452
Reviewed-by: David Ostrovsky <David.Ostrovsky@gmx.de>
Tested-by: David Ostrovsky <David.Ostrovsky@gmx.de>

pyuno/source/loader/pyuno_loader.cxx

@@ -223,6 +223,10 @@ Reference< XInterface > CreateInstance( const Reference< XComponentContext > & c
 
         PyThreadState *tstate = PyThreadState_Get();
         PyEval_ReleaseThread( tstate );
+        // This tstate is never used again, so delete it here.
+        // This prevents an assertion in PyThreadState_Swap on the
+        // PyThreadAttach below.
+        PyThreadState_Delete(tstate);
     }
 
     PyThreadAttach attach( PyInterpreterState_Head() );