git-extra: make pkgver slightly smarter

An update to the `pkgver` itself is not considered to be a vital change
to `git-extra`, therefore tip commits touching only that line are
excluded from the calculation of the package version.

However, running an `/updpkgsums` may very well update also a checksum
(which was exactly the case in
#591 (comment))
and such a change should _likewise_ avoid advancing the `pkgver`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

git-extra/PKGBUILD

@@ -21,7 +21,7 @@ pkgver() {
   test ! -f "$(git rev-parse --git-path shallow)" || git -c http.sslbackend fetch --unshallow
   rev="$(git rev-list -1 HEAD -- .)"
   test -n "$(git show . |
-    sed -n -e '1,/^@@/d' -e '/^[-+]pkgver=/d' -e '/^[-+]/p')" ||
+    sed -n -e '1,/^@@/d' -e '/^[-+]pkgver=/d' -e '/^[-+]pkgver=/d' -e "/^[-+] *'[0-9a-f]\{64\}'$/d" -e '/^[-+]/p')" ||
   rev="$(git rev-list -1 $rev^ -- .)"
   printf "%s.%s.%s" "${_ver_base}" "$(git rev-list --count $rev -- .)" \
     "$(git rev-parse --short=9 $rev)"