Fix freeze when clicking on 'Help' menu in editor

The functions med-mark-start and med-mark-end don't exist - that's fine, still read the rest of the menus, so it can actually properly 'hide' the help menu after it's clicked on.

common/ui/menubar.cpp

@@ -817,7 +817,6 @@ int menubar_init( const char * file )
 			if (!item.user_function)
 			{
 				con_printf(CON_URGENT, "%s:%u: unknown function \"%s\" in \"%s\"", __FILE__, __LINE__, buf1, file);
-				break;
 			}
 		}