Project manager: grab focus on ok button after path selection.

Slight usability improvement: grabs focus on the Import/Create button after engine.cfg/path selection.
So then I can just press enter to create the project ^^

(cherry picked from commit 36d2dd5318f5a021d6956a772cd7fc288e222253)

tools/editor/project_manager.cpp

@@ -142,6 +142,7 @@ private:
 		String sp = p.simplify_path();
 		project_path->set_text(sp);
 		_path_text_changed(p);
+		get_ok()->call_deferred("grab_focus");
 	}
 
 	void _path_selected(const String& p_path) {
@@ -150,7 +151,7 @@ private:
 		String sp = p.simplify_path();
 		project_path->set_text(sp);
 		_path_text_changed(p);
-
+		get_ok()->call_deferred("grab_focus");
 	}
 
 	void _browse_path() {