mod_dav: Sending a If or If-Match header with an invalid ETag doesn't

result in a 412 Precondition Failed.

PR: 54610
Submitted by: Timothy Wood <tjw omnigroup com>
Backports: r1476604 (2.4: r1486456)
Reviewed by: minfrin, wrowe, rjung

rjung plans to mention that this is for the COPY method only (in CHANGES
of 2.2 and 2.4 branches and these three commit messages).



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1497441 13f79535-47bb-0310-9956-ffa450edef68