Install OperationCallback for all executed JS scripts

JS doors with the "Use Shell or New Context" option enabled in SCFG and JS
modules installed a global hot key handlers would not automatically terminate
when the user disconnected (and js.auto_terminate was true, the default).
I'm not sure why the operation callback was only installed when scope==NULL
but always installing it fixes the issue with some global hot key modules
and JS doors becoming "zombies" when a user disconnects while running them.

src/sbbs3/exec.cpp

@@ -679,13 +679,8 @@ long sbbs_t::js_execfile(const char *cmd, const char* startup_dir, JSObject* sco
 
 	if(scope==NULL) {
 		js_callback.counter=0;	// Reset loop counter
-
-#if JS_VERSION>180
-		JS_SetOperationCallback(js_cx, js_OperationCallback);
-#else
-		JS_SetBranchCallback(js_cx, js_BranchCallback);
-#endif
 	}
+	JS_SetOperationCallback(js_cx, js_OperationCallback);
 	js_PrepareToExecute(js_cx, js_glob, path, startup_dir, js_scope);
 	events = js_callback.events;
 	js_callback.events = NULL;