git-svn has not supported GIT_SVN_NO_OPTIMIZE_COMMITS for
the "set-tree" sub-command in 9 years since commit
490f49ea5899
("git-svn: remove optimized commit stuff for set-tree").
So remove this target and TSVN variable to avoid confusion.
ref: http://mid.gmane.org/
56C9B7B7.
7030406@f2.dion.ne.jp
Helped-by: Kazutoshi Satoda <k_satoda@f2.dion.ne.jp>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>