[geany/geany] a62595: Provide error message for extract regex

[Lex Trotman]

  Branch: refs/heads/master
  Home:   https://github.com/geany/geany

  Commit: a625955a43a484fbd23f9585cc4f4f4f256e87b5
      https://github.com/geany/geany/commit/a625955a43a484fbd23f9585cc4f4f4f256e87b5
  Author: Lex Trotman <elextr at gmail.com>
  Date:   2011-11-13 (Sun, 13 Nov 2011)

  Changed paths:
    M src/filetypes.c

  Log Message:
  -----------
  Provide error message for extract regex

Print the GError message if the users filetype extract regex does
not compile.