tests: stop worrying about obsolete environment variables

After v0.99.7~99 (Retire support for old environment variables,
2005-09-09), there is no more need to unset a stray AUTHOR_NAME
variable that might have entered the test environment.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/test-lib.sh

@@ -44,11 +44,6 @@ export LANG LC_ALL PAGER TERM TZ
 EDITOR=:
 unset VISUAL
 unset GIT_EDITOR
-unset AUTHOR_DATE
-unset AUTHOR_EMAIL
-unset AUTHOR_NAME
-unset COMMIT_AUTHOR_EMAIL
-unset COMMIT_AUTHOR_NAME
 unset EMAIL
 unset GIT_ALTERNATE_OBJECT_DIRECTORIES
 unset GIT_AUTHOR_DATE
@@ -64,8 +59,6 @@ unset GIT_EXTERNAL_DIFF
 unset GIT_INDEX_FILE
 unset GIT_OBJECT_DIRECTORY
 unset GIT_CEILING_DIRECTORIES
-unset SHA1_FILE_DIRECTORIES
-unset SHA1_FILE_DIRECTORY
 unset GIT_NOTES_REF
 unset GIT_NOTES_DISPLAY_REF
 unset GIT_NOTES_REWRITE_REF