remove v->threaded, as it's a local variable now

Author: Michiel Jan Laurens de Hoon

Modules/_tkinter.c

@@ -639,12 +639,6 @@ Tkapp_New(const char *screenName, const char *className,
     }
 #endif
     v->wantobjects = wantobjects;
-#if TCL_MAJOR_VERSION >= 9
-    v->threaded = 1;
-#else
-    v->threaded = Tcl_GetVar2Ex(v->interp, "tcl_platform", "threaded",
-                                TCL_GLOBAL_ONLY) != NULL;
-#endif
     v->thread_id = Tcl_GetCurrentThread();
     v->dispatching = 0;
     v->trace = NULL;