Remove obscure check for package build time from --rebuilddb (rpm-sof…

…tware-management#2527)

Back in 1997, commit be0b903 added a
sanity check for --rebuilddb operation, skipping headers which lack
some basic tags. Name, version and release are real requirements for
packages, but checking for buildtime is odd, and plain wrong.
Yes, we expect that to be present in packages built by rpm, but that's
not used for any processing and certainly is not required for a package
to be installable. And if it can be installed then it can't be
right to throw it away when rebuilding, leaving untrackable orphan
files in the process.

It is also documented as informational and optional by LSB. While
severely outdated, it is right on this account.

Fixes: rpm-software-management#2527

lib/rpmdb.c

@@ -2470,8 +2470,7 @@ int rpmdbRebuild(const char * prefix, rpmts ts,
 	    /* let's sanity check this record a bit, otherwise just skip it */
 	    if (!(headerIsEntry(h, RPMTAG_NAME) &&
 		headerIsEntry(h, RPMTAG_VERSION) &&
-		headerIsEntry(h, RPMTAG_RELEASE) &&
-		headerIsEntry(h, RPMTAG_BUILDTIME)))
+		headerIsEntry(h, RPMTAG_RELEASE)))
 	    {
 		rpmlog(RPMLOG_ERR,
 			_("header #%u in the database is bad -- skipping.\n"),