Fix generator to avoid build warnings and failures if serf is not used.
Fix generator to avoid build warnings and failures if serf is not used.

* build/generator/gen_win.py
  (get_install_targets): Drop serf from target list if we don't have it.



git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@860518 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion