Fix signature for 'folder_moved' signal of FileSystemDock

doc/classes/FileSystemDock.xml

@@ -32,7 +32,7 @@
 		</signal>
 		<signal name="folder_moved">
 			<param index="0" name="old_folder" type="String" />
-			<param index="1" name="new_file" type="String" />
+			<param index="1" name="new_folder" type="String" />
 			<description>
 			</description>
 		</signal>

editor/filesystem_dock.cpp

@@ -2994,7 +2994,7 @@ void FileSystemDock::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("file_removed", PropertyInfo(Variant::STRING, "file")));
 	ADD_SIGNAL(MethodInfo("folder_removed", PropertyInfo(Variant::STRING, "folder")));
 	ADD_SIGNAL(MethodInfo("files_moved", PropertyInfo(Variant::STRING, "old_file"), PropertyInfo(Variant::STRING, "new_file")));
-	ADD_SIGNAL(MethodInfo("folder_moved", PropertyInfo(Variant::STRING, "old_folder"), PropertyInfo(Variant::STRING, "new_file")));
+	ADD_SIGNAL(MethodInfo("folder_moved", PropertyInfo(Variant::STRING, "old_folder"), PropertyInfo(Variant::STRING, "new_folder")));
 
 	ADD_SIGNAL(MethodInfo("display_mode_changed"));
 }