Only add our option headers in the mod_dav_svn OPTIONS handler if the client asks for our option(s). This avoids setting them over and over again if a client asks for a list of options at once.
Only add our option headers in the mod_dav_svn OPTIONS handler if the client
asks for our option(s). This avoids setting them over and over again if a
client asks for a list of options at once.

* subversion/mod_dav_svn/version.c
  (get_option): Following up on r1557094, only add our option headers when
    asked for our option; not for every (undefined) option.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1557103 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion