updated to 7.4.873

updated to 7.4.873

7.4.866  crash when changing the 'tags' option from a remote command
7.4.867  (after 7.4.866) can't build on MS-Windows
7.4.868  'smarttab' is also effective when 'paste' is enabled
7.4.869  MS-Windows with Intel GPU: scroll may cause text to disappear
7.4.870  get into an invalid state when using getchar() in expr mapping
7.4.871  Vim leaks memory when 'wildignore' filters out all matches
7.4.872  not using CI services available
7.4.873  (after 7.4.866) compiler warning for unused variable